diff mbox series

drm/bridge: synopsys: dw-mipi-dsi: fix deferred dsi host probe breaks dsi device probe

Message ID 20240112180737.551318-1-farouk.bouabid@theobroma-systems.com
State New
Headers
Series drm/bridge: synopsys: dw-mipi-dsi: fix deferred dsi host probe breaks dsi device probe |

Commit Message

Farouk Bouabid Jan. 12, 2024, 6:07 p.m. UTC 
  dw-mipi-dsi based drivers such as dw-mipi-dsi-rockchip or dw_mipi_dsi-stm
depend on dw_mipi_dsi_probe() to initialize the dw_mipi_dsi driver
structure (dmd pointer). This structure is only initialized once
dw_mipi_dsi_probe() returns, creating the link between the locally created
structure and the actual dmd pointer.

Probing the dsi host can be deferred in case of dependency to a dsi
phy-supply (eg. "rockchip,px30-dsi-dphy"). Meanwhile dsi-device drivers
like panels (eg. "ltk050h3146w") can already be registered on the bus.
In that case, when attempting, to register the dsi host from
dw_mipi_dsi_probe() using mipi_dsi_host_register(), the panel probe is
called with a dsi-host pointer that is still locally allocated in
dw_mipi_dsi_probe().

While probing, the panel driver tries to attach to a dsi host
(mipi_dsi_attach()) which calls in return for the specific dsi host
attach hook. (e.g. dw_mipi_dsi_rockchip_host_attach()).
dw_mipi_dsi_rockchip uses the component framework.
In the attach hook, the host component is registered which calls in return
for drm_bridge_attach() while trying to bind the component
(dw_mipi_dsi_bind())

drm_bridge_attach() requires a valid drm bridge parameter. However, the
drm bridge (&dmd->bridge) that will be passed, is not yet initialized since
the dw_mipi_dsi_probe() has not yet returned. This call will fail with a
fatal error (invalid bridge) causing the panel to not be probed again.

To simplify the issue: drm_bridge_attach() depends on the result pointer
of dw_mipi_dsi_probe().
While, if the dsi probe is deferred, drm_bridge_attach() is called before
dw_mipi_dsi_probe() returns.

drm_bridge_attach+0x14/0x1ac
dw_mipi_dsi_bind+0x24/0x30
dw_mipi_dsi_rockchip_bind+0x258/0x378
component_bind_all+0x118/0x248
rockchip_drm_bind+0xb0/0x1f8
try_to_bring_up_aggregate_device+0x168/0x1d4
__component_add+0xa4/0x170
component_add+0x14/0x20
dw_mipi_dsi_rockchip_host_attach+0x54/0x144
dw_mipi_dsi_host_attach+0x9c/0xcc
mipi_dsi_attach+0x28/0x3c
ltk050h3146w_probe+0x10c/0x1a4
mipi_dsi_drv_probe+0x20/0x2c
really_probe+0x148/0x2ac
__driver_probe_device+0x78/0x12c
driver_probe_device+0xdc/0x160
__device_attach_driver+0xb8/0x134
bus_for_each_drv+0x80/0xdc
__device_attach+0xa8/0x1b0
device_initial_probe+0x14/0x20
bus_probe_device+0xa8/0xac
device_add+0x5cc/0x778
mipi_dsi_device_register_full+0xd8/0x198
mipi_dsi_host_register+0x98/0x18c
__dw_mipi_dsi_probe+0x290/0x35c
dw_mipi_dsi_probe+0x10/0x6c
dw_mipi_dsi_rockchip_probe+0x208/0x3e4
platform_probe+0x68/0xdc
really_probe+0x148/0x2ac
__driver_probe_device+0x78/0x12c
driver_probe_device+0xdc/0x160
__device_attach_driver+0xb8/0x134
bus_for_each_drv+0x80/0xdc
__device_attach+0xa8/0x1b0
device_initial_probe+0x14/0x20
bus_probe_device+0xa8/0xac
deferred_probe_work_func+0x88/0xc0
process_one_work+0x138/0x260
worker_thread+0x32c/0x438
kthread+0x118/0x11c
ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---

Fix this by initializing directly the dmd pointer in dw_mipi_dsi_probe(),
which requires also initializting the dmd->bridge attributes that are
required in drm_bridge_attach() before calling mipi_dsi_host_register().

Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
---
 drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c   |  4 +-
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 42 ++++++++++---------
 drivers/gpu/drm/meson/meson_dw_mipi_dsi.c     |  8 ++--
 .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c   |  5 +--
 drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         |  5 +--
 include/drm/bridge/dw_mipi_dsi.h              |  5 ++-
 6 files changed, 35 insertions(+), 34 deletions(-)

Comments

Neil Armstrong Jan. 15, 2024, 8:45 a.m. UTC | #1 
Hi,

On 12/01/2024 19:07, Farouk Bouabid wrote:
> dw-mipi-dsi based drivers such as dw-mipi-dsi-rockchip or dw_mipi_dsi-stm
> depend on dw_mipi_dsi_probe() to initialize the dw_mipi_dsi driver
> structure (dmd pointer). This structure is only initialized once
> dw_mipi_dsi_probe() returns, creating the link between the locally created
> structure and the actual dmd pointer.
> 
> Probing the dsi host can be deferred in case of dependency to a dsi
> phy-supply (eg. "rockchip,px30-dsi-dphy"). Meanwhile dsi-device drivers
> like panels (eg. "ltk050h3146w") can already be registered on the bus.
> In that case, when attempting, to register the dsi host from
> dw_mipi_dsi_probe() using mipi_dsi_host_register(), the panel probe is
> called with a dsi-host pointer that is still locally allocated in
> dw_mipi_dsi_probe().
> 
> While probing, the panel driver tries to attach to a dsi host
> (mipi_dsi_attach()) which calls in return for the specific dsi host
> attach hook. (e.g. dw_mipi_dsi_rockchip_host_attach()).
> dw_mipi_dsi_rockchip uses the component framework.
> In the attach hook, the host component is registered which calls in return
> for drm_bridge_attach() while trying to bind the component
> (dw_mipi_dsi_bind())

In meson_dw_mipi_dsi I simply fixed this by getting rid of components...

Neil

> 
> drm_bridge_attach() requires a valid drm bridge parameter. However, the
> drm bridge (&dmd->bridge) that will be passed, is not yet initialized since
> the dw_mipi_dsi_probe() has not yet returned. This call will fail with a
> fatal error (invalid bridge) causing the panel to not be probed again.
> 
> To simplify the issue: drm_bridge_attach() depends on the result pointer
> of dw_mipi_dsi_probe().
> While, if the dsi probe is deferred, drm_bridge_attach() is called before
> dw_mipi_dsi_probe() returns.
> 
> drm_bridge_attach+0x14/0x1ac
> dw_mipi_dsi_bind+0x24/0x30
> dw_mipi_dsi_rockchip_bind+0x258/0x378
> component_bind_all+0x118/0x248
> rockchip_drm_bind+0xb0/0x1f8
> try_to_bring_up_aggregate_device+0x168/0x1d4
> __component_add+0xa4/0x170
> component_add+0x14/0x20
> dw_mipi_dsi_rockchip_host_attach+0x54/0x144
> dw_mipi_dsi_host_attach+0x9c/0xcc
> mipi_dsi_attach+0x28/0x3c
> ltk050h3146w_probe+0x10c/0x1a4
> mipi_dsi_drv_probe+0x20/0x2c
> really_probe+0x148/0x2ac
> __driver_probe_device+0x78/0x12c
> driver_probe_device+0xdc/0x160
> __device_attach_driver+0xb8/0x134
> bus_for_each_drv+0x80/0xdc
> __device_attach+0xa8/0x1b0
> device_initial_probe+0x14/0x20
> bus_probe_device+0xa8/0xac
> device_add+0x5cc/0x778
> mipi_dsi_device_register_full+0xd8/0x198
> mipi_dsi_host_register+0x98/0x18c
> __dw_mipi_dsi_probe+0x290/0x35c
> dw_mipi_dsi_probe+0x10/0x6c
> dw_mipi_dsi_rockchip_probe+0x208/0x3e4
> platform_probe+0x68/0xdc
> really_probe+0x148/0x2ac
> __driver_probe_device+0x78/0x12c
> driver_probe_device+0xdc/0x160
> __device_attach_driver+0xb8/0x134
> bus_for_each_drv+0x80/0xdc
> __device_attach+0xa8/0x1b0
> device_initial_probe+0x14/0x20
> bus_probe_device+0xa8/0xac
> deferred_probe_work_func+0x88/0xc0
> process_one_work+0x138/0x260
> worker_thread+0x32c/0x438
> kthread+0x118/0x11c
> ret_from_fork+0x10/0x20
> ---[ end trace 0000000000000000 ]---
> 
> Fix this by initializing directly the dmd pointer in dw_mipi_dsi_probe(),
> which requires also initializting the dmd->bridge attributes that are
> required in drm_bridge_attach() before calling mipi_dsi_host_register().
> 
> Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
> ---
>   drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c   |  4 +-
>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 42 ++++++++++---------
>   drivers/gpu/drm/meson/meson_dw_mipi_dsi.c     |  8 ++--
>   .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c   |  5 +--
>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         |  5 +--
>   include/drm/bridge/dw_mipi_dsi.h              |  5 ++-
>   6 files changed, 35 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c b/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
> index 3ff30ce80c5b..469976ad3b19 100644
> --- a/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
> @@ -881,8 +881,8 @@ static int imx93_dsi_probe(struct platform_device *pdev)
>   	dsi->pdata.priv_data = dsi;
>   	platform_set_drvdata(pdev, dsi);
>   
> -	dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
> -	if (IS_ERR(dsi->dmd))
> +	ret = dw_mipi_dsi_probe(pdev, &dsi->pdata, &dsi->dmd);
> +	if (ret < 0)
>   		return dev_err_probe(dev, PTR_ERR(dsi->dmd),
>   				     "failed to probe dw_mipi_dsi\n");
>   
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 824fb3c65742..306cba366ba8 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -1184,18 +1184,19 @@ static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi) { }
>   
>   #endif /* CONFIG_DEBUG_FS */
>   
> -static struct dw_mipi_dsi *
> -__dw_mipi_dsi_probe(struct platform_device *pdev,
> -		    const struct dw_mipi_dsi_plat_data *plat_data)
> +int __dw_mipi_dsi_probe(struct platform_device *pdev,
> +		    const struct dw_mipi_dsi_plat_data *plat_data, struct dw_mipi_dsi **dsi_p)
>   {
>   	struct device *dev = &pdev->dev;
>   	struct reset_control *apb_rst;
>   	struct dw_mipi_dsi *dsi;
>   	int ret;
>   
> -	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> -	if (!dsi)
> -		return ERR_PTR(-ENOMEM);
> +	*dsi_p = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> +	if (!*dsi_p)
> +		return -ENOMEM;
> +
> +	dsi = *dsi_p;
>   
>   	dsi->dev = dev;
>   	dsi->plat_data = plat_data;
> @@ -1203,13 +1204,13 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>   	if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps ||
>   	    !plat_data->phy_ops->get_timing) {
>   		DRM_ERROR("Phy not properly configured\n");
> -		return ERR_PTR(-ENODEV);
> +		return -ENODEV;
>   	}
>   
>   	if (!plat_data->base) {
>   		dsi->base = devm_platform_ioremap_resource(pdev, 0);
>   		if (IS_ERR(dsi->base))
> -			return ERR_PTR(-ENODEV);
> +			return -ENODEV;
>   
>   	} else {
>   		dsi->base = plat_data->base;
> @@ -1219,7 +1220,7 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>   	if (IS_ERR(dsi->pclk)) {
>   		ret = PTR_ERR(dsi->pclk);
>   		dev_err(dev, "Unable to get pclk: %d\n", ret);
> -		return ERR_PTR(ret);
> +		return ret;
>   	}
>   
>   	/*
> @@ -1233,14 +1234,14 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>   		if (ret != -EPROBE_DEFER)
>   			dev_err(dev, "Unable to get reset control: %d\n", ret);
>   
> -		return ERR_PTR(ret);
> +		return ret;
>   	}
>   
>   	if (apb_rst) {
>   		ret = clk_prepare_enable(dsi->pclk);
>   		if (ret) {
>   			dev_err(dev, "%s: Failed to enable pclk\n", __func__);
> -			return ERR_PTR(ret);
> +			return ret;
>   		}
>   
>   		reset_control_assert(apb_rst);
> @@ -1255,19 +1256,20 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>   
>   	dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
>   	dsi->dsi_host.dev = dev;
> +	dsi->bridge.driver_private = dsi;
> +	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
> +	dsi->bridge.of_node = pdev->dev.of_node;
> +
>   	ret = mipi_dsi_host_register(&dsi->dsi_host);
>   	if (ret) {
>   		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
>   		pm_runtime_disable(dev);
>   		dw_mipi_dsi_debugfs_remove(dsi);
> -		return ERR_PTR(ret);
> +		return ret;
>   	}
>   
> -	dsi->bridge.driver_private = dsi;
> -	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
> -	dsi->bridge.of_node = pdev->dev.of_node;
>   
> -	return dsi;
> +	return 0;
>   }
>   
>   static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
> @@ -1301,11 +1303,11 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_get_bridge);
>   /*
>    * Probe/remove API, used from platforms based on the DRM bridge API.
>    */
> -struct dw_mipi_dsi *
> -dw_mipi_dsi_probe(struct platform_device *pdev,
> -		  const struct dw_mipi_dsi_plat_data *plat_data)
> +int dw_mipi_dsi_probe(struct platform_device *pdev,
> +		  const struct dw_mipi_dsi_plat_data *plat_data,
> +		  struct dw_mipi_dsi **dsi_p)
>   {
> -	return __dw_mipi_dsi_probe(pdev, plat_data);
> +	return __dw_mipi_dsi_probe(pdev, plat_data, dsi_p);
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>   
> diff --git a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> index e5fe4e994f43..b103f3e31f2a 100644
> --- a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> @@ -262,6 +262,7 @@ static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
>   {
>   	struct meson_dw_mipi_dsi *mipi_dsi;
>   	struct device *dev = &pdev->dev;
> +	int ret;
>   
>   	mipi_dsi = devm_kzalloc(dev, sizeof(*mipi_dsi), GFP_KERNEL);
>   	if (!mipi_dsi)
> @@ -315,10 +316,9 @@ static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
>   	mipi_dsi->pdata.priv_data = mipi_dsi;
>   	platform_set_drvdata(pdev, mipi_dsi);
>   
> -	mipi_dsi->dmd = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata);
> -	if (IS_ERR(mipi_dsi->dmd))
> -		return dev_err_probe(dev, PTR_ERR(mipi_dsi->dmd),
> -				     "Failed to probe dw_mipi_dsi\n");
> +	ret = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata, &mipi_dsi->dmd);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "Failed to probe dw_mipi_dsi\n");
>   
>   	return 0;
>   }
> diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> index 6396f9324dab..4df32747476c 100644
> --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> @@ -1457,9 +1457,8 @@ static int dw_mipi_dsi_rockchip_probe(struct platform_device *pdev)
>   	if (IS_ERR(phy_provider))
>   		return PTR_ERR(phy_provider);
>   
> -	dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
> -	if (IS_ERR(dsi->dmd)) {
> -		ret = PTR_ERR(dsi->dmd);
> +	ret = dw_mipi_dsi_probe(pdev, &dsi->pdata, &dsi->dmd);
> +	if (ret < 0) {
>   		if (ret != -EPROBE_DEFER)
>   			DRM_DEV_ERROR(dev,
>   				      "Failed to probe dw_mipi_dsi: %d\n", ret);
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index d5f8c923d7bc..44dbbfc277d8 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -518,9 +518,8 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   
>   	platform_set_drvdata(pdev, dsi);
>   
> -	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> -	if (IS_ERR(dsi->dsi)) {
> -		ret = PTR_ERR(dsi->dsi);
> +	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data, &dsi->dsi);
> +	if (ret < 0) {
>   		dev_err_probe(dev, ret, "Failed to initialize mipi dsi host\n");
>   		goto err_dsi_probe;
>   	}
> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
> index 65d5e68065e3..f073e819251e 100644
> --- a/include/drm/bridge/dw_mipi_dsi.h
> +++ b/include/drm/bridge/dw_mipi_dsi.h
> @@ -76,9 +76,10 @@ struct dw_mipi_dsi_plat_data {
>   	void *priv_data;
>   };
>   
> -struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> +int dw_mipi_dsi_probe(struct platform_device *pdev,
>   				      const struct dw_mipi_dsi_plat_data
> -				      *plat_data);
> +				      *plat_data,
> +					  struct dw_mipi_dsi **dsi_p);
>   void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
>   int dw_mipi_dsi_bind(struct dw_mipi_dsi *dsi, struct drm_encoder *encoder);
>   void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
Heiko Stübner Jan. 15, 2024, 10:07 a.m. UTC | #2 
Am Montag, 15. Januar 2024, 09:45:10 CET schrieb neil.armstrong@linaro.org:
> Hi,
> 
> On 12/01/2024 19:07, Farouk Bouabid wrote:
> > dw-mipi-dsi based drivers such as dw-mipi-dsi-rockchip or dw_mipi_dsi-stm
> > depend on dw_mipi_dsi_probe() to initialize the dw_mipi_dsi driver
> > structure (dmd pointer). This structure is only initialized once
> > dw_mipi_dsi_probe() returns, creating the link between the locally created
> > structure and the actual dmd pointer.
> > 
> > Probing the dsi host can be deferred in case of dependency to a dsi
> > phy-supply (eg. "rockchip,px30-dsi-dphy"). Meanwhile dsi-device drivers
> > like panels (eg. "ltk050h3146w") can already be registered on the bus.
> > In that case, when attempting, to register the dsi host from
> > dw_mipi_dsi_probe() using mipi_dsi_host_register(), the panel probe is
> > called with a dsi-host pointer that is still locally allocated in
> > dw_mipi_dsi_probe().
> > 
> > While probing, the panel driver tries to attach to a dsi host
> > (mipi_dsi_attach()) which calls in return for the specific dsi host
> > attach hook. (e.g. dw_mipi_dsi_rockchip_host_attach()).
> > dw_mipi_dsi_rockchip uses the component framework.
> > In the attach hook, the host component is registered which calls in return
> > for drm_bridge_attach() while trying to bind the component
> > (dw_mipi_dsi_bind())
> 
> In meson_dw_mipi_dsi I simply fixed this by getting rid of components...

If I remember correctly, the component element is there on Rockchip to
facilitate running dual-dsi displays (1 panel driven by 2 dsi controllers),
because it allows to wait for both controllers to have probed individually
before trying to drive the display.

Not sure if there is a better way to do that now.


Heiko


> > drm_bridge_attach() requires a valid drm bridge parameter. However, the
> > drm bridge (&dmd->bridge) that will be passed, is not yet initialized since
> > the dw_mipi_dsi_probe() has not yet returned. This call will fail with a
> > fatal error (invalid bridge) causing the panel to not be probed again.
> > 
> > To simplify the issue: drm_bridge_attach() depends on the result pointer
> > of dw_mipi_dsi_probe().
> > While, if the dsi probe is deferred, drm_bridge_attach() is called before
> > dw_mipi_dsi_probe() returns.
> > 
> > drm_bridge_attach+0x14/0x1ac
> > dw_mipi_dsi_bind+0x24/0x30
> > dw_mipi_dsi_rockchip_bind+0x258/0x378
> > component_bind_all+0x118/0x248
> > rockchip_drm_bind+0xb0/0x1f8
> > try_to_bring_up_aggregate_device+0x168/0x1d4
> > __component_add+0xa4/0x170
> > component_add+0x14/0x20
> > dw_mipi_dsi_rockchip_host_attach+0x54/0x144
> > dw_mipi_dsi_host_attach+0x9c/0xcc
> > mipi_dsi_attach+0x28/0x3c
> > ltk050h3146w_probe+0x10c/0x1a4
> > mipi_dsi_drv_probe+0x20/0x2c
> > really_probe+0x148/0x2ac
> > __driver_probe_device+0x78/0x12c
> > driver_probe_device+0xdc/0x160
> > __device_attach_driver+0xb8/0x134
> > bus_for_each_drv+0x80/0xdc
> > __device_attach+0xa8/0x1b0
> > device_initial_probe+0x14/0x20
> > bus_probe_device+0xa8/0xac
> > device_add+0x5cc/0x778
> > mipi_dsi_device_register_full+0xd8/0x198
> > mipi_dsi_host_register+0x98/0x18c
> > __dw_mipi_dsi_probe+0x290/0x35c
> > dw_mipi_dsi_probe+0x10/0x6c
> > dw_mipi_dsi_rockchip_probe+0x208/0x3e4
> > platform_probe+0x68/0xdc
> > really_probe+0x148/0x2ac
> > __driver_probe_device+0x78/0x12c
> > driver_probe_device+0xdc/0x160
> > __device_attach_driver+0xb8/0x134
> > bus_for_each_drv+0x80/0xdc
> > __device_attach+0xa8/0x1b0
> > device_initial_probe+0x14/0x20
> > bus_probe_device+0xa8/0xac
> > deferred_probe_work_func+0x88/0xc0
> > process_one_work+0x138/0x260
> > worker_thread+0x32c/0x438
> > kthread+0x118/0x11c
> > ret_from_fork+0x10/0x20
> > ---[ end trace 0000000000000000 ]---
> > 
> > Fix this by initializing directly the dmd pointer in dw_mipi_dsi_probe(),
> > which requires also initializting the dmd->bridge attributes that are
> > required in drm_bridge_attach() before calling mipi_dsi_host_register().
> > 
> > Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
> > ---
> >   drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c   |  4 +-
> >   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 42 ++++++++++---------
> >   drivers/gpu/drm/meson/meson_dw_mipi_dsi.c     |  8 ++--
> >   .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c   |  5 +--
> >   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         |  5 +--
> >   include/drm/bridge/dw_mipi_dsi.h              |  5 ++-
> >   6 files changed, 35 insertions(+), 34 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c b/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
> > index 3ff30ce80c5b..469976ad3b19 100644
> > --- a/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
> > +++ b/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
> > @@ -881,8 +881,8 @@ static int imx93_dsi_probe(struct platform_device *pdev)
> >   	dsi->pdata.priv_data = dsi;
> >   	platform_set_drvdata(pdev, dsi);
> >   
> > -	dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
> > -	if (IS_ERR(dsi->dmd))
> > +	ret = dw_mipi_dsi_probe(pdev, &dsi->pdata, &dsi->dmd);
> > +	if (ret < 0)
> >   		return dev_err_probe(dev, PTR_ERR(dsi->dmd),
> >   				     "failed to probe dw_mipi_dsi\n");
> >   
> > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > index 824fb3c65742..306cba366ba8 100644
> > --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > @@ -1184,18 +1184,19 @@ static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi) { }
> >   
> >   #endif /* CONFIG_DEBUG_FS */
> >   
> > -static struct dw_mipi_dsi *
> > -__dw_mipi_dsi_probe(struct platform_device *pdev,
> > -		    const struct dw_mipi_dsi_plat_data *plat_data)
> > +int __dw_mipi_dsi_probe(struct platform_device *pdev,
> > +		    const struct dw_mipi_dsi_plat_data *plat_data, struct dw_mipi_dsi **dsi_p)
> >   {
> >   	struct device *dev = &pdev->dev;
> >   	struct reset_control *apb_rst;
> >   	struct dw_mipi_dsi *dsi;
> >   	int ret;
> >   
> > -	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> > -	if (!dsi)
> > -		return ERR_PTR(-ENOMEM);
> > +	*dsi_p = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> > +	if (!*dsi_p)
> > +		return -ENOMEM;
> > +
> > +	dsi = *dsi_p;
> >   
> >   	dsi->dev = dev;
> >   	dsi->plat_data = plat_data;
> > @@ -1203,13 +1204,13 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
> >   	if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps ||
> >   	    !plat_data->phy_ops->get_timing) {
> >   		DRM_ERROR("Phy not properly configured\n");
> > -		return ERR_PTR(-ENODEV);
> > +		return -ENODEV;
> >   	}
> >   
> >   	if (!plat_data->base) {
> >   		dsi->base = devm_platform_ioremap_resource(pdev, 0);
> >   		if (IS_ERR(dsi->base))
> > -			return ERR_PTR(-ENODEV);
> > +			return -ENODEV;
> >   
> >   	} else {
> >   		dsi->base = plat_data->base;
> > @@ -1219,7 +1220,7 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
> >   	if (IS_ERR(dsi->pclk)) {
> >   		ret = PTR_ERR(dsi->pclk);
> >   		dev_err(dev, "Unable to get pclk: %d\n", ret);
> > -		return ERR_PTR(ret);
> > +		return ret;
> >   	}
> >   
> >   	/*
> > @@ -1233,14 +1234,14 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
> >   		if (ret != -EPROBE_DEFER)
> >   			dev_err(dev, "Unable to get reset control: %d\n", ret);
> >   
> > -		return ERR_PTR(ret);
> > +		return ret;
> >   	}
> >   
> >   	if (apb_rst) {
> >   		ret = clk_prepare_enable(dsi->pclk);
> >   		if (ret) {
> >   			dev_err(dev, "%s: Failed to enable pclk\n", __func__);
> > -			return ERR_PTR(ret);
> > +			return ret;
> >   		}
> >   
> >   		reset_control_assert(apb_rst);
> > @@ -1255,19 +1256,20 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
> >   
> >   	dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
> >   	dsi->dsi_host.dev = dev;
> > +	dsi->bridge.driver_private = dsi;
> > +	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
> > +	dsi->bridge.of_node = pdev->dev.of_node;
> > +
> >   	ret = mipi_dsi_host_register(&dsi->dsi_host);
> >   	if (ret) {
> >   		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
> >   		pm_runtime_disable(dev);
> >   		dw_mipi_dsi_debugfs_remove(dsi);
> > -		return ERR_PTR(ret);
> > +		return ret;
> >   	}
> >   
> > -	dsi->bridge.driver_private = dsi;
> > -	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
> > -	dsi->bridge.of_node = pdev->dev.of_node;
> >   
> > -	return dsi;
> > +	return 0;
> >   }
> >   
> >   static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
> > @@ -1301,11 +1303,11 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_get_bridge);
> >   /*
> >    * Probe/remove API, used from platforms based on the DRM bridge API.
> >    */
> > -struct dw_mipi_dsi *
> > -dw_mipi_dsi_probe(struct platform_device *pdev,
> > -		  const struct dw_mipi_dsi_plat_data *plat_data)
> > +int dw_mipi_dsi_probe(struct platform_device *pdev,
> > +		  const struct dw_mipi_dsi_plat_data *plat_data,
> > +		  struct dw_mipi_dsi **dsi_p)
> >   {
> > -	return __dw_mipi_dsi_probe(pdev, plat_data);
> > +	return __dw_mipi_dsi_probe(pdev, plat_data, dsi_p);
> >   }
> >   EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
> >   
> > diff --git a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> > index e5fe4e994f43..b103f3e31f2a 100644
> > --- a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> > +++ b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> > @@ -262,6 +262,7 @@ static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
> >   {
> >   	struct meson_dw_mipi_dsi *mipi_dsi;
> >   	struct device *dev = &pdev->dev;
> > +	int ret;
> >   
> >   	mipi_dsi = devm_kzalloc(dev, sizeof(*mipi_dsi), GFP_KERNEL);
> >   	if (!mipi_dsi)
> > @@ -315,10 +316,9 @@ static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
> >   	mipi_dsi->pdata.priv_data = mipi_dsi;
> >   	platform_set_drvdata(pdev, mipi_dsi);
> >   
> > -	mipi_dsi->dmd = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata);
> > -	if (IS_ERR(mipi_dsi->dmd))
> > -		return dev_err_probe(dev, PTR_ERR(mipi_dsi->dmd),
> > -				     "Failed to probe dw_mipi_dsi\n");
> > +	ret = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata, &mipi_dsi->dmd);
> > +	if (ret < 0)
> > +		return dev_err_probe(dev, ret, "Failed to probe dw_mipi_dsi\n");
> >   
> >   	return 0;
> >   }
> > diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> > index 6396f9324dab..4df32747476c 100644
> > --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> > +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> > @@ -1457,9 +1457,8 @@ static int dw_mipi_dsi_rockchip_probe(struct platform_device *pdev)
> >   	if (IS_ERR(phy_provider))
> >   		return PTR_ERR(phy_provider);
> >   
> > -	dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
> > -	if (IS_ERR(dsi->dmd)) {
> > -		ret = PTR_ERR(dsi->dmd);
> > +	ret = dw_mipi_dsi_probe(pdev, &dsi->pdata, &dsi->dmd);
> > +	if (ret < 0) {
> >   		if (ret != -EPROBE_DEFER)
> >   			DRM_DEV_ERROR(dev,
> >   				      "Failed to probe dw_mipi_dsi: %d\n", ret);
> > diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> > index d5f8c923d7bc..44dbbfc277d8 100644
> > --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> > +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> > @@ -518,9 +518,8 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
> >   
> >   	platform_set_drvdata(pdev, dsi);
> >   
> > -	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> > -	if (IS_ERR(dsi->dsi)) {
> > -		ret = PTR_ERR(dsi->dsi);
> > +	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data, &dsi->dsi);
> > +	if (ret < 0) {
> >   		dev_err_probe(dev, ret, "Failed to initialize mipi dsi host\n");
> >   		goto err_dsi_probe;
> >   	}
> > diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
> > index 65d5e68065e3..f073e819251e 100644
> > --- a/include/drm/bridge/dw_mipi_dsi.h
> > +++ b/include/drm/bridge/dw_mipi_dsi.h
> > @@ -76,9 +76,10 @@ struct dw_mipi_dsi_plat_data {
> >   	void *priv_data;
> >   };
> >   
> > -struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> > +int dw_mipi_dsi_probe(struct platform_device *pdev,
> >   				      const struct dw_mipi_dsi_plat_data
> > -				      *plat_data);
> > +				      *plat_data,
> > +					  struct dw_mipi_dsi **dsi_p);
> >   void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
> >   int dw_mipi_dsi_bind(struct dw_mipi_dsi *dsi, struct drm_encoder *encoder);
> >   void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
> 
>
Neil Armstrong Jan. 15, 2024, 12:52 p.m. UTC | #3 
On 15/01/2024 11:07, Heiko Stübner wrote:
> Am Montag, 15. Januar 2024, 09:45:10 CET schrieb neil.armstrong@linaro.org:
>> Hi,
>>
>> On 12/01/2024 19:07, Farouk Bouabid wrote:
>>> dw-mipi-dsi based drivers such as dw-mipi-dsi-rockchip or dw_mipi_dsi-stm
>>> depend on dw_mipi_dsi_probe() to initialize the dw_mipi_dsi driver
>>> structure (dmd pointer). This structure is only initialized once
>>> dw_mipi_dsi_probe() returns, creating the link between the locally created
>>> structure and the actual dmd pointer.
>>>
>>> Probing the dsi host can be deferred in case of dependency to a dsi
>>> phy-supply (eg. "rockchip,px30-dsi-dphy"). Meanwhile dsi-device drivers
>>> like panels (eg. "ltk050h3146w") can already be registered on the bus.
>>> In that case, when attempting, to register the dsi host from
>>> dw_mipi_dsi_probe() using mipi_dsi_host_register(), the panel probe is
>>> called with a dsi-host pointer that is still locally allocated in
>>> dw_mipi_dsi_probe().
>>>
>>> While probing, the panel driver tries to attach to a dsi host
>>> (mipi_dsi_attach()) which calls in return for the specific dsi host
>>> attach hook. (e.g. dw_mipi_dsi_rockchip_host_attach()).
>>> dw_mipi_dsi_rockchip uses the component framework.
>>> In the attach hook, the host component is registered which calls in return
>>> for drm_bridge_attach() while trying to bind the component
>>> (dw_mipi_dsi_bind())
>>
>> In meson_dw_mipi_dsi I simply fixed this by getting rid of components...
> 
> If I remember correctly, the component element is there on Rockchip to
> facilitate running dual-dsi displays (1 panel driven by 2 dsi controllers),
> because it allows to wait for both controllers to have probed individually
> before trying to drive the display.
> 
> Not sure if there is a better way to do that now.

Device links should limit probe deferal to a minimum, at least it works fine
on the systems I work on

Neil

> 
> 
> Heiko
> 
> 
>>> drm_bridge_attach() requires a valid drm bridge parameter. However, the
>>> drm bridge (&dmd->bridge) that will be passed, is not yet initialized since
>>> the dw_mipi_dsi_probe() has not yet returned. This call will fail with a
>>> fatal error (invalid bridge) causing the panel to not be probed again.
>>>
>>> To simplify the issue: drm_bridge_attach() depends on the result pointer
>>> of dw_mipi_dsi_probe().
>>> While, if the dsi probe is deferred, drm_bridge_attach() is called before
>>> dw_mipi_dsi_probe() returns.
>>>
>>> drm_bridge_attach+0x14/0x1ac
>>> dw_mipi_dsi_bind+0x24/0x30
>>> dw_mipi_dsi_rockchip_bind+0x258/0x378
>>> component_bind_all+0x118/0x248
>>> rockchip_drm_bind+0xb0/0x1f8
>>> try_to_bring_up_aggregate_device+0x168/0x1d4
>>> __component_add+0xa4/0x170
>>> component_add+0x14/0x20
>>> dw_mipi_dsi_rockchip_host_attach+0x54/0x144
>>> dw_mipi_dsi_host_attach+0x9c/0xcc
>>> mipi_dsi_attach+0x28/0x3c
>>> ltk050h3146w_probe+0x10c/0x1a4
>>> mipi_dsi_drv_probe+0x20/0x2c
>>> really_probe+0x148/0x2ac
>>> __driver_probe_device+0x78/0x12c
>>> driver_probe_device+0xdc/0x160
>>> __device_attach_driver+0xb8/0x134
>>> bus_for_each_drv+0x80/0xdc
>>> __device_attach+0xa8/0x1b0
>>> device_initial_probe+0x14/0x20
>>> bus_probe_device+0xa8/0xac
>>> device_add+0x5cc/0x778
>>> mipi_dsi_device_register_full+0xd8/0x198
>>> mipi_dsi_host_register+0x98/0x18c
>>> __dw_mipi_dsi_probe+0x290/0x35c
>>> dw_mipi_dsi_probe+0x10/0x6c
>>> dw_mipi_dsi_rockchip_probe+0x208/0x3e4
>>> platform_probe+0x68/0xdc
>>> really_probe+0x148/0x2ac
>>> __driver_probe_device+0x78/0x12c
>>> driver_probe_device+0xdc/0x160
>>> __device_attach_driver+0xb8/0x134
>>> bus_for_each_drv+0x80/0xdc
>>> __device_attach+0xa8/0x1b0
>>> device_initial_probe+0x14/0x20
>>> bus_probe_device+0xa8/0xac
>>> deferred_probe_work_func+0x88/0xc0
>>> process_one_work+0x138/0x260
>>> worker_thread+0x32c/0x438
>>> kthread+0x118/0x11c
>>> ret_from_fork+0x10/0x20
>>> ---[ end trace 0000000000000000 ]---
>>>
>>> Fix this by initializing directly the dmd pointer in dw_mipi_dsi_probe(),
>>> which requires also initializting the dmd->bridge attributes that are
>>> required in drm_bridge_attach() before calling mipi_dsi_host_register().
>>>
>>> Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
>>> ---
>>>    drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c   |  4 +-
>>>    drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 42 ++++++++++---------
>>>    drivers/gpu/drm/meson/meson_dw_mipi_dsi.c     |  8 ++--
>>>    .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c   |  5 +--
>>>    drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         |  5 +--
>>>    include/drm/bridge/dw_mipi_dsi.h              |  5 ++-
>>>    6 files changed, 35 insertions(+), 34 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c b/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
>>> index 3ff30ce80c5b..469976ad3b19 100644
>>> --- a/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
>>> +++ b/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
>>> @@ -881,8 +881,8 @@ static int imx93_dsi_probe(struct platform_device *pdev)
>>>    	dsi->pdata.priv_data = dsi;
>>>    	platform_set_drvdata(pdev, dsi);
>>>    
>>> -	dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
>>> -	if (IS_ERR(dsi->dmd))
>>> +	ret = dw_mipi_dsi_probe(pdev, &dsi->pdata, &dsi->dmd);
>>> +	if (ret < 0)
>>>    		return dev_err_probe(dev, PTR_ERR(dsi->dmd),
>>>    				     "failed to probe dw_mipi_dsi\n");
>>>    
>>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>> index 824fb3c65742..306cba366ba8 100644
>>> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>> @@ -1184,18 +1184,19 @@ static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi) { }
>>>    
>>>    #endif /* CONFIG_DEBUG_FS */
>>>    
>>> -static struct dw_mipi_dsi *
>>> -__dw_mipi_dsi_probe(struct platform_device *pdev,
>>> -		    const struct dw_mipi_dsi_plat_data *plat_data)
>>> +int __dw_mipi_dsi_probe(struct platform_device *pdev,
>>> +		    const struct dw_mipi_dsi_plat_data *plat_data, struct dw_mipi_dsi **dsi_p)
>>>    {
>>>    	struct device *dev = &pdev->dev;
>>>    	struct reset_control *apb_rst;
>>>    	struct dw_mipi_dsi *dsi;
>>>    	int ret;
>>>    
>>> -	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
>>> -	if (!dsi)
>>> -		return ERR_PTR(-ENOMEM);
>>> +	*dsi_p = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
>>> +	if (!*dsi_p)
>>> +		return -ENOMEM;
>>> +
>>> +	dsi = *dsi_p;
>>>    
>>>    	dsi->dev = dev;
>>>    	dsi->plat_data = plat_data;
>>> @@ -1203,13 +1204,13 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>>>    	if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps ||
>>>    	    !plat_data->phy_ops->get_timing) {
>>>    		DRM_ERROR("Phy not properly configured\n");
>>> -		return ERR_PTR(-ENODEV);
>>> +		return -ENODEV;
>>>    	}
>>>    
>>>    	if (!plat_data->base) {
>>>    		dsi->base = devm_platform_ioremap_resource(pdev, 0);
>>>    		if (IS_ERR(dsi->base))
>>> -			return ERR_PTR(-ENODEV);
>>> +			return -ENODEV;
>>>    
>>>    	} else {
>>>    		dsi->base = plat_data->base;
>>> @@ -1219,7 +1220,7 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>>>    	if (IS_ERR(dsi->pclk)) {
>>>    		ret = PTR_ERR(dsi->pclk);
>>>    		dev_err(dev, "Unable to get pclk: %d\n", ret);
>>> -		return ERR_PTR(ret);
>>> +		return ret;
>>>    	}
>>>    
>>>    	/*
>>> @@ -1233,14 +1234,14 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>>>    		if (ret != -EPROBE_DEFER)
>>>    			dev_err(dev, "Unable to get reset control: %d\n", ret);
>>>    
>>> -		return ERR_PTR(ret);
>>> +		return ret;
>>>    	}
>>>    
>>>    	if (apb_rst) {
>>>    		ret = clk_prepare_enable(dsi->pclk);
>>>    		if (ret) {
>>>    			dev_err(dev, "%s: Failed to enable pclk\n", __func__);
>>> -			return ERR_PTR(ret);
>>> +			return ret;
>>>    		}
>>>    
>>>    		reset_control_assert(apb_rst);
>>> @@ -1255,19 +1256,20 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>>>    
>>>    	dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
>>>    	dsi->dsi_host.dev = dev;
>>> +	dsi->bridge.driver_private = dsi;
>>> +	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
>>> +	dsi->bridge.of_node = pdev->dev.of_node;
>>> +
>>>    	ret = mipi_dsi_host_register(&dsi->dsi_host);
>>>    	if (ret) {
>>>    		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
>>>    		pm_runtime_disable(dev);
>>>    		dw_mipi_dsi_debugfs_remove(dsi);
>>> -		return ERR_PTR(ret);
>>> +		return ret;
>>>    	}
>>>    
>>> -	dsi->bridge.driver_private = dsi;
>>> -	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
>>> -	dsi->bridge.of_node = pdev->dev.of_node;
>>>    
>>> -	return dsi;
>>> +	return 0;
>>>    }
>>>    
>>>    static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>>> @@ -1301,11 +1303,11 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_get_bridge);
>>>    /*
>>>     * Probe/remove API, used from platforms based on the DRM bridge API.
>>>     */
>>> -struct dw_mipi_dsi *
>>> -dw_mipi_dsi_probe(struct platform_device *pdev,
>>> -		  const struct dw_mipi_dsi_plat_data *plat_data)
>>> +int dw_mipi_dsi_probe(struct platform_device *pdev,
>>> +		  const struct dw_mipi_dsi_plat_data *plat_data,
>>> +		  struct dw_mipi_dsi **dsi_p)
>>>    {
>>> -	return __dw_mipi_dsi_probe(pdev, plat_data);
>>> +	return __dw_mipi_dsi_probe(pdev, plat_data, dsi_p);
>>>    }
>>>    EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>>>    
>>> diff --git a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
>>> index e5fe4e994f43..b103f3e31f2a 100644
>>> --- a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
>>> +++ b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
>>> @@ -262,6 +262,7 @@ static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
>>>    {
>>>    	struct meson_dw_mipi_dsi *mipi_dsi;
>>>    	struct device *dev = &pdev->dev;
>>> +	int ret;
>>>    
>>>    	mipi_dsi = devm_kzalloc(dev, sizeof(*mipi_dsi), GFP_KERNEL);
>>>    	if (!mipi_dsi)
>>> @@ -315,10 +316,9 @@ static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
>>>    	mipi_dsi->pdata.priv_data = mipi_dsi;
>>>    	platform_set_drvdata(pdev, mipi_dsi);
>>>    
>>> -	mipi_dsi->dmd = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata);
>>> -	if (IS_ERR(mipi_dsi->dmd))
>>> -		return dev_err_probe(dev, PTR_ERR(mipi_dsi->dmd),
>>> -				     "Failed to probe dw_mipi_dsi\n");
>>> +	ret = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata, &mipi_dsi->dmd);
>>> +	if (ret < 0)
>>> +		return dev_err_probe(dev, ret, "Failed to probe dw_mipi_dsi\n");
>>>    
>>>    	return 0;
>>>    }
>>> diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
>>> index 6396f9324dab..4df32747476c 100644
>>> --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
>>> +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
>>> @@ -1457,9 +1457,8 @@ static int dw_mipi_dsi_rockchip_probe(struct platform_device *pdev)
>>>    	if (IS_ERR(phy_provider))
>>>    		return PTR_ERR(phy_provider);
>>>    
>>> -	dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
>>> -	if (IS_ERR(dsi->dmd)) {
>>> -		ret = PTR_ERR(dsi->dmd);
>>> +	ret = dw_mipi_dsi_probe(pdev, &dsi->pdata, &dsi->dmd);
>>> +	if (ret < 0) {
>>>    		if (ret != -EPROBE_DEFER)
>>>    			DRM_DEV_ERROR(dev,
>>>    				      "Failed to probe dw_mipi_dsi: %d\n", ret);
>>> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>>> index d5f8c923d7bc..44dbbfc277d8 100644
>>> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>>> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>>> @@ -518,9 +518,8 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>>>    
>>>    	platform_set_drvdata(pdev, dsi);
>>>    
>>> -	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
>>> -	if (IS_ERR(dsi->dsi)) {
>>> -		ret = PTR_ERR(dsi->dsi);
>>> +	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data, &dsi->dsi);
>>> +	if (ret < 0) {
>>>    		dev_err_probe(dev, ret, "Failed to initialize mipi dsi host\n");
>>>    		goto err_dsi_probe;
>>>    	}
>>> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
>>> index 65d5e68065e3..f073e819251e 100644
>>> --- a/include/drm/bridge/dw_mipi_dsi.h
>>> +++ b/include/drm/bridge/dw_mipi_dsi.h
>>> @@ -76,9 +76,10 @@ struct dw_mipi_dsi_plat_data {
>>>    	void *priv_data;
>>>    };
>>>    
>>> -struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
>>> +int dw_mipi_dsi_probe(struct platform_device *pdev,
>>>    				      const struct dw_mipi_dsi_plat_data
>>> -				      *plat_data);
>>> +				      *plat_data,
>>> +					  struct dw_mipi_dsi **dsi_p);
>>>    void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
>>>    int dw_mipi_dsi_bind(struct dw_mipi_dsi *dsi, struct drm_encoder *encoder);
>>>    void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
>>
>>
> 
> 
> 
>
kernel test robot Jan. 15, 2024, 5:54 p.m. UTC | #4 
Hi Farouk,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on drm/drm-next linus/master v6.7 next-20240112]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Farouk-Bouabid/drm-bridge-synopsys-dw-mipi-dsi-fix-deferred-dsi-host-probe-breaks-dsi-device-probe/20240113-020945
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20240112180737.551318-1-farouk.bouabid%40theobroma-systems.com
patch subject: [PATCH] drm/bridge: synopsys: dw-mipi-dsi: fix deferred dsi host probe breaks dsi device probe
config: i386-buildonly-randconfig-002-20240115 (https://download.01.org/0day-ci/archive/20240116/202401160108.j5Lqkppm-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240116/202401160108.j5Lqkppm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401160108.j5Lqkppm-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c:1187:5: warning: no previous prototype for '__dw_mipi_dsi_probe' [-Wmissing-prototypes]
    1187 | int __dw_mipi_dsi_probe(struct platform_device *pdev,
         |     ^~~~~~~~~~~~~~~~~~~


vim +/__dw_mipi_dsi_probe +1187 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

  1186	
> 1187	int __dw_mipi_dsi_probe(struct platform_device *pdev,
  1188			    const struct dw_mipi_dsi_plat_data *plat_data, struct dw_mipi_dsi **dsi_p)
  1189	{
  1190		struct device *dev = &pdev->dev;
  1191		struct reset_control *apb_rst;
  1192		struct dw_mipi_dsi *dsi;
  1193		int ret;
  1194	
  1195		*dsi_p = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
  1196		if (!*dsi_p)
  1197			return -ENOMEM;
  1198	
  1199		dsi = *dsi_p;
  1200	
  1201		dsi->dev = dev;
  1202		dsi->plat_data = plat_data;
  1203	
  1204		if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps ||
  1205		    !plat_data->phy_ops->get_timing) {
  1206			DRM_ERROR("Phy not properly configured\n");
  1207			return -ENODEV;
  1208		}
  1209	
  1210		if (!plat_data->base) {
  1211			dsi->base = devm_platform_ioremap_resource(pdev, 0);
  1212			if (IS_ERR(dsi->base))
  1213				return -ENODEV;
  1214	
  1215		} else {
  1216			dsi->base = plat_data->base;
  1217		}
  1218	
  1219		dsi->pclk = devm_clk_get(dev, "pclk");
  1220		if (IS_ERR(dsi->pclk)) {
  1221			ret = PTR_ERR(dsi->pclk);
  1222			dev_err(dev, "Unable to get pclk: %d\n", ret);
  1223			return ret;
  1224		}
  1225	
  1226		/*
  1227		 * Note that the reset was not defined in the initial device tree, so
  1228		 * we have to be prepared for it not being found.
  1229		 */
  1230		apb_rst = devm_reset_control_get_optional_exclusive(dev, "apb");
  1231		if (IS_ERR(apb_rst)) {
  1232			ret = PTR_ERR(apb_rst);
  1233	
  1234			if (ret != -EPROBE_DEFER)
  1235				dev_err(dev, "Unable to get reset control: %d\n", ret);
  1236	
  1237			return ret;
  1238		}
  1239	
  1240		if (apb_rst) {
  1241			ret = clk_prepare_enable(dsi->pclk);
  1242			if (ret) {
  1243				dev_err(dev, "%s: Failed to enable pclk\n", __func__);
  1244				return ret;
  1245			}
  1246	
  1247			reset_control_assert(apb_rst);
  1248			usleep_range(10, 20);
  1249			reset_control_deassert(apb_rst);
  1250	
  1251			clk_disable_unprepare(dsi->pclk);
  1252		}
  1253	
  1254		dw_mipi_dsi_debugfs_init(dsi);
  1255		pm_runtime_enable(dev);
  1256	
  1257		dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
  1258		dsi->dsi_host.dev = dev;
  1259		dsi->bridge.driver_private = dsi;
  1260		dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
  1261		dsi->bridge.of_node = pdev->dev.of_node;
  1262	
  1263		ret = mipi_dsi_host_register(&dsi->dsi_host);
  1264		if (ret) {
  1265			dev_err(dev, "Failed to register MIPI host: %d\n", ret);
  1266			pm_runtime_disable(dev);
  1267			dw_mipi_dsi_debugfs_remove(dsi);
  1268			return ret;
  1269		}
  1270	
  1271	
  1272		return 0;
  1273	}
  1274
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c b/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
index 3ff30ce80c5b..469976ad3b19 100644
--- a/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c
@@ -881,8 +881,8 @@  static int imx93_dsi_probe(struct platform_device *pdev)
 	dsi->pdata.priv_data = dsi;
 	platform_set_drvdata(pdev, dsi);
 
-	dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
-	if (IS_ERR(dsi->dmd))
+	ret = dw_mipi_dsi_probe(pdev, &dsi->pdata, &dsi->dmd);
+	if (ret < 0)
 		return dev_err_probe(dev, PTR_ERR(dsi->dmd),
 				     "failed to probe dw_mipi_dsi\n");
 
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 824fb3c65742..306cba366ba8 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -1184,18 +1184,19 @@  static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi) { }
 
 #endif /* CONFIG_DEBUG_FS */
 
-static struct dw_mipi_dsi *
-__dw_mipi_dsi_probe(struct platform_device *pdev,
-		    const struct dw_mipi_dsi_plat_data *plat_data)
+int __dw_mipi_dsi_probe(struct platform_device *pdev,
+		    const struct dw_mipi_dsi_plat_data *plat_data, struct dw_mipi_dsi **dsi_p)
 {
 	struct device *dev = &pdev->dev;
 	struct reset_control *apb_rst;
 	struct dw_mipi_dsi *dsi;
 	int ret;
 
-	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
-	if (!dsi)
-		return ERR_PTR(-ENOMEM);
+	*dsi_p = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
+	if (!*dsi_p)
+		return -ENOMEM;
+
+	dsi = *dsi_p;
 
 	dsi->dev = dev;
 	dsi->plat_data = plat_data;
@@ -1203,13 +1204,13 @@  __dw_mipi_dsi_probe(struct platform_device *pdev,
 	if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps ||
 	    !plat_data->phy_ops->get_timing) {
 		DRM_ERROR("Phy not properly configured\n");
-		return ERR_PTR(-ENODEV);
+		return -ENODEV;
 	}
 
 	if (!plat_data->base) {
 		dsi->base = devm_platform_ioremap_resource(pdev, 0);
 		if (IS_ERR(dsi->base))
-			return ERR_PTR(-ENODEV);
+			return -ENODEV;
 
 	} else {
 		dsi->base = plat_data->base;
@@ -1219,7 +1220,7 @@  __dw_mipi_dsi_probe(struct platform_device *pdev,
 	if (IS_ERR(dsi->pclk)) {
 		ret = PTR_ERR(dsi->pclk);
 		dev_err(dev, "Unable to get pclk: %d\n", ret);
-		return ERR_PTR(ret);
+		return ret;
 	}
 
 	/*
@@ -1233,14 +1234,14 @@  __dw_mipi_dsi_probe(struct platform_device *pdev,
 		if (ret != -EPROBE_DEFER)
 			dev_err(dev, "Unable to get reset control: %d\n", ret);
 
-		return ERR_PTR(ret);
+		return ret;
 	}
 
 	if (apb_rst) {
 		ret = clk_prepare_enable(dsi->pclk);
 		if (ret) {
 			dev_err(dev, "%s: Failed to enable pclk\n", __func__);
-			return ERR_PTR(ret);
+			return ret;
 		}
 
 		reset_control_assert(apb_rst);
@@ -1255,19 +1256,20 @@  __dw_mipi_dsi_probe(struct platform_device *pdev,
 
 	dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
 	dsi->dsi_host.dev = dev;
+	dsi->bridge.driver_private = dsi;
+	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
+	dsi->bridge.of_node = pdev->dev.of_node;
+
 	ret = mipi_dsi_host_register(&dsi->dsi_host);
 	if (ret) {
 		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
 		pm_runtime_disable(dev);
 		dw_mipi_dsi_debugfs_remove(dsi);
-		return ERR_PTR(ret);
+		return ret;
 	}
 
-	dsi->bridge.driver_private = dsi;
-	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
-	dsi->bridge.of_node = pdev->dev.of_node;
 
-	return dsi;
+	return 0;
 }
 
 static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
@@ -1301,11 +1303,11 @@  EXPORT_SYMBOL_GPL(dw_mipi_dsi_get_bridge);
 /*
  * Probe/remove API, used from platforms based on the DRM bridge API.
  */
-struct dw_mipi_dsi *
-dw_mipi_dsi_probe(struct platform_device *pdev,
-		  const struct dw_mipi_dsi_plat_data *plat_data)
+int dw_mipi_dsi_probe(struct platform_device *pdev,
+		  const struct dw_mipi_dsi_plat_data *plat_data,
+		  struct dw_mipi_dsi **dsi_p)
 {
-	return __dw_mipi_dsi_probe(pdev, plat_data);
+	return __dw_mipi_dsi_probe(pdev, plat_data, dsi_p);
 }
 EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
 
diff --git a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
index e5fe4e994f43..b103f3e31f2a 100644
--- a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
+++ b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
@@ -262,6 +262,7 @@  static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
 {
 	struct meson_dw_mipi_dsi *mipi_dsi;
 	struct device *dev = &pdev->dev;
+	int ret;
 
 	mipi_dsi = devm_kzalloc(dev, sizeof(*mipi_dsi), GFP_KERNEL);
 	if (!mipi_dsi)
@@ -315,10 +316,9 @@  static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
 	mipi_dsi->pdata.priv_data = mipi_dsi;
 	platform_set_drvdata(pdev, mipi_dsi);
 
-	mipi_dsi->dmd = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata);
-	if (IS_ERR(mipi_dsi->dmd))
-		return dev_err_probe(dev, PTR_ERR(mipi_dsi->dmd),
-				     "Failed to probe dw_mipi_dsi\n");
+	ret = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata, &mipi_dsi->dmd);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to probe dw_mipi_dsi\n");
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
index 6396f9324dab..4df32747476c 100644
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
@@ -1457,9 +1457,8 @@  static int dw_mipi_dsi_rockchip_probe(struct platform_device *pdev)
 	if (IS_ERR(phy_provider))
 		return PTR_ERR(phy_provider);
 
-	dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
-	if (IS_ERR(dsi->dmd)) {
-		ret = PTR_ERR(dsi->dmd);
+	ret = dw_mipi_dsi_probe(pdev, &dsi->pdata, &dsi->dmd);
+	if (ret < 0) {
 		if (ret != -EPROBE_DEFER)
 			DRM_DEV_ERROR(dev,
 				      "Failed to probe dw_mipi_dsi: %d\n", ret);
diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index d5f8c923d7bc..44dbbfc277d8 100644
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -518,9 +518,8 @@  static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, dsi);
 
-	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
-	if (IS_ERR(dsi->dsi)) {
-		ret = PTR_ERR(dsi->dsi);
+	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data, &dsi->dsi);
+	if (ret < 0) {
 		dev_err_probe(dev, ret, "Failed to initialize mipi dsi host\n");
 		goto err_dsi_probe;
 	}
diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
index 65d5e68065e3..f073e819251e 100644
--- a/include/drm/bridge/dw_mipi_dsi.h
+++ b/include/drm/bridge/dw_mipi_dsi.h
@@ -76,9 +76,10 @@  struct dw_mipi_dsi_plat_data {
 	void *priv_data;
 };
 
-struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
+int dw_mipi_dsi_probe(struct platform_device *pdev,
 				      const struct dw_mipi_dsi_plat_data
-				      *plat_data);
+				      *plat_data,
+					  struct dw_mipi_dsi **dsi_p);
 void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
 int dw_mipi_dsi_bind(struct dw_mipi_dsi *dsi, struct drm_encoder *encoder);
 void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);