diff mbox series

[V7,6/7] remoteproc: imx_rproc: request mbox channel later

Message ID 20221014031037.1070424-7-peng.fan@oss.nxp.com
State New
Headers
Series remoteproc: imx_rproc: support i.MX8QM/QXP |

Commit Message

Peng Fan (OSS) Oct. 14, 2022, 3:10 a.m. UTC 
  From: Peng Fan <peng.fan@nxp.com>

It is possible that when remote processor crash, the communication
channel will be broken with garbage value in mailbox, such as
when Linux is issuing a message through mailbox, remote processor
crashes, we need free & rebuild the mailbox channels to make sure
no garbage value in mailbox channels.

So move the request/free to start/stop for managing remote procesosr in
Linux, move to attach/detach for remote processor is out of control of
Linux.

Previous, we just request mbox when attach for CM4 boot early before
Linux, but if mbox defer probe, remoteproc core will do resource cleanup
and corrupt resource table for later probe.

So move request mbox ealier and still keep mbox request when attach
for self recovery case, but keep a check when request/free mbox.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/remoteproc/imx_rproc.c | 39 ++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

Comments

Mathieu Poirier Oct. 14, 2022, 5:49 p.m. UTC | #1 
On Fri, Oct 14, 2022 at 11:10:36AM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> It is possible that when remote processor crash, the communication
> channel will be broken with garbage value in mailbox, such as
> when Linux is issuing a message through mailbox, remote processor
> crashes, we need free & rebuild the mailbox channels to make sure
> no garbage value in mailbox channels.
> 
> So move the request/free to start/stop for managing remote procesosr in
> Linux, move to attach/detach for remote processor is out of control of
> Linux.
> 
> Previous, we just request mbox when attach for CM4 boot early before
> Linux, but if mbox defer probe, remoteproc core will do resource cleanup
> and corrupt resource table for later probe.
> 
> So move request mbox ealier and still keep mbox request when attach
> for self recovery case, but keep a check when request/free mbox.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/remoteproc/imx_rproc.c | 39 ++++++++++++++++++++++++++++++++--
>  1 file changed, 37 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
> index 917e6db39572..1183de84a4c0 100644
> --- a/drivers/remoteproc/imx_rproc.c
> +++ b/drivers/remoteproc/imx_rproc.c
> @@ -84,6 +84,8 @@ struct imx_rproc_mem {
>  #define ATT_CORE_MASK   0xffff
>  #define ATT_CORE(I)     BIT((I))
>  
> +static int imx_rproc_xtr_mbox_init(struct rproc *rproc);
> +static void imx_rproc_free_mbox(struct rproc *rproc);
>  static int imx_rproc_detach_pd(struct rproc *rproc);
>  
>  struct imx_rproc {
> @@ -357,6 +359,10 @@ static int imx_rproc_start(struct rproc *rproc)
>  	struct arm_smccc_res res;
>  	int ret;
>  
> +	ret = imx_rproc_xtr_mbox_init(rproc);
> +	if (ret)
> +		return ret;
> +
>  	switch (dcfg->method) {
>  	case IMX_RPROC_MMIO:
>  		ret = regmap_update_bits(priv->regmap, dcfg->src_reg, dcfg->src_mask,
> @@ -407,6 +413,8 @@ static int imx_rproc_stop(struct rproc *rproc)
>  
>  	if (ret)
>  		dev_err(dev, "Failed to stop remote core\n");
> +	else
> +		imx_rproc_free_mbox(rproc);
>  
>  	return ret;
>  }
> @@ -592,6 +600,22 @@ static void imx_rproc_kick(struct rproc *rproc, int vqid)
>  
>  static int imx_rproc_attach(struct rproc *rproc)
>  {
> +	return imx_rproc_xtr_mbox_init(rproc);
> +}
> +
> +static int imx_rproc_detach(struct rproc *rproc)
> +{
> +	struct imx_rproc *priv = rproc->priv;
> +	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
> +
> +	if (dcfg->method != IMX_RPROC_SCU_API)
> +		return -EOPNOTSUPP;
> +
> +	if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
> +		return -EOPNOTSUPP;
> +
> +	imx_rproc_free_mbox(rproc);
> +
>  	return 0;
>  }
>  
> @@ -610,6 +634,7 @@ static struct resource_table *imx_rproc_get_loaded_rsc_table(struct rproc *rproc
>  static const struct rproc_ops imx_rproc_ops = {
>  	.prepare	= imx_rproc_prepare,
>  	.attach		= imx_rproc_attach,
> +	.detach		= imx_rproc_detach,
>  	.start		= imx_rproc_start,
>  	.stop		= imx_rproc_stop,
>  	.kick		= imx_rproc_kick,
> @@ -720,6 +745,9 @@ static int imx_rproc_xtr_mbox_init(struct rproc *rproc)
>  	struct device *dev = priv->dev;
>  	struct mbox_client *cl;
>  
> +	if (priv->tx_ch && priv->rx_ch)
> +		return 0;
> +

You did exactly the same things as in V6.  I asked you why this is needed and
all you did is point me to the code in _probe(), which I can read on my own.

Again - why is this needed when we know it will be done in start() and attach()?


>  	if (!of_get_property(dev->of_node, "mbox-names", NULL))
>  		return 0;
>  
> @@ -749,8 +777,15 @@ static void imx_rproc_free_mbox(struct rproc *rproc)
>  {
>  	struct imx_rproc *priv = rproc->priv;
>  
> -	mbox_free_channel(priv->tx_ch);
> -	mbox_free_channel(priv->rx_ch);
> +	if (priv->tx_ch) {
> +		mbox_free_channel(priv->tx_ch);
> +		priv->tx_ch = NULL;
> +	}
> +
> +	if (priv->rx_ch) {
> +		mbox_free_channel(priv->rx_ch);
> +		priv->rx_ch = NULL;
> +	}
>  }
>  
>  static void imx_rproc_put_scu(struct rproc *rproc)
> -- 
> 2.37.1
>
Peng Fan Oct. 17, 2022, 3:13 a.m. UTC | #2 
Hi Mathieu,

> Subject: Re: [PATCH V7 6/7] remoteproc: imx_rproc: request mbox channel
> later
> 
> On Fri, Oct 14, 2022 at 11:10:36AM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@nxp.com>
> >
> > It is possible that when remote processor crash, the communication
> > channel will be broken with garbage value in mailbox, such as when
> > Linux is issuing a message through mailbox, remote processor crashes,
> > we need free & rebuild the mailbox channels to make sure no garbage
> > value in mailbox channels.
> >
> > So move the request/free to start/stop for managing remote procesosr
> > in Linux, move to attach/detach for remote processor is out of control
> > of Linux.
> >
> > Previous, we just request mbox when attach for CM4 boot early before
> > Linux, but if mbox defer probe, remoteproc core will do resource
> > cleanup and corrupt resource table for later probe.
> >
> > So move request mbox ealier and still keep mbox request when attach
> > for self recovery case, but keep a check when request/free mbox.
> >
> > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > ---
> >  drivers/remoteproc/imx_rproc.c | 39
> > ++++++++++++++++++++++++++++++++--
> >  1 file changed, 37 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/remoteproc/imx_rproc.c
> > b/drivers/remoteproc/imx_rproc.c index 917e6db39572..1183de84a4c0
> > 100644
> > --- a/drivers/remoteproc/imx_rproc.c
> > +++ b/drivers/remoteproc/imx_rproc.c
> > @@ -84,6 +84,8 @@ struct imx_rproc_mem {
> >  #define ATT_CORE_MASK   0xffff
> >  #define ATT_CORE(I)     BIT((I))
> >
> > +static int imx_rproc_xtr_mbox_init(struct rproc *rproc); static void
> > +imx_rproc_free_mbox(struct rproc *rproc);
> >  static int imx_rproc_detach_pd(struct rproc *rproc);
> >
> >  struct imx_rproc {
> > @@ -357,6 +359,10 @@ static int imx_rproc_start(struct rproc *rproc)
> >  	struct arm_smccc_res res;
> >  	int ret;
> >
> > +	ret = imx_rproc_xtr_mbox_init(rproc);
> > +	if (ret)
> > +		return ret;
> > +
> >  	switch (dcfg->method) {
> >  	case IMX_RPROC_MMIO:
> >  		ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
> > dcfg->src_mask, @@ -407,6 +413,8 @@ static int imx_rproc_stop(struct
> > rproc *rproc)
> >
> >  	if (ret)
> >  		dev_err(dev, "Failed to stop remote core\n");
> > +	else
> > +		imx_rproc_free_mbox(rproc);
> >
> >  	return ret;
> >  }
> > @@ -592,6 +600,22 @@ static void imx_rproc_kick(struct rproc *rproc,
> > int vqid)
> >
> >  static int imx_rproc_attach(struct rproc *rproc)  {
> > +	return imx_rproc_xtr_mbox_init(rproc); }
> > +
> > +static int imx_rproc_detach(struct rproc *rproc) {
> > +	struct imx_rproc *priv = rproc->priv;
> > +	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
> > +
> > +	if (dcfg->method != IMX_RPROC_SCU_API)
> > +		return -EOPNOTSUPP;
> > +
> > +	if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
> > +		return -EOPNOTSUPP;
> > +
> > +	imx_rproc_free_mbox(rproc);
> > +
> >  	return 0;
> >  }
> >
> > @@ -610,6 +634,7 @@ static struct resource_table
> > *imx_rproc_get_loaded_rsc_table(struct rproc *rproc  static const struct
> rproc_ops imx_rproc_ops = {
> >  	.prepare	= imx_rproc_prepare,
> >  	.attach		= imx_rproc_attach,
> > +	.detach		= imx_rproc_detach,
> >  	.start		= imx_rproc_start,
> >  	.stop		= imx_rproc_stop,
> >  	.kick		= imx_rproc_kick,
> > @@ -720,6 +745,9 @@ static int imx_rproc_xtr_mbox_init(struct rproc
> *rproc)
> >  	struct device *dev = priv->dev;
> >  	struct mbox_client *cl;
> >
> > +	if (priv->tx_ch && priv->rx_ch)
> > +		return 0;
> > +
> 
> You did exactly the same things as in V6.  I asked you why this is needed and
> all you did is point me to the code in _probe(), which I can read on my own.
> 

Sorry for not wrote down clear.

> Again - why is this needed when we know it will be done in start() and
> attach()?

start() and attach() not able to handle mbox defer probe. So I add
the mbox requesting in probe to handle mbox defer probe, and add
a check when requesting mbox channel in start/attach. During first
time attach/start remote core, the imx_rproc_xtr_mbox_init just
return, because channel requested in probe flow. 

Since mbox requested in probe, why still add it in start() and attach()?
It is to support runtime stop and start(M4 is under control of Linux),
to support runtime detach(only for i.MX8QM/QXP attach recovery,
m4 out of control from linux) and attach.

Thanks,
Peng.
> 
> 
> >  	if (!of_get_property(dev->of_node, "mbox-names", NULL))
> >  		return 0;
> >
> > @@ -749,8 +777,15 @@ static void imx_rproc_free_mbox(struct rproc
> > *rproc)  {
> >  	struct imx_rproc *priv = rproc->priv;
> >
> > -	mbox_free_channel(priv->tx_ch);
> > -	mbox_free_channel(priv->rx_ch);
> > +	if (priv->tx_ch) {
> > +		mbox_free_channel(priv->tx_ch);
> > +		priv->tx_ch = NULL;
> > +	}
> > +
> > +	if (priv->rx_ch) {
> > +		mbox_free_channel(priv->rx_ch);
> > +		priv->rx_ch = NULL;
> > +	}
> >  }
> >
> >  static void imx_rproc_put_scu(struct rproc *rproc)
> > --
> > 2.37.1
> >
Mathieu Poirier Oct. 17, 2022, 5:33 p.m. UTC | #3 
On Mon, Oct 17, 2022 at 03:13:16AM +0000, Peng Fan wrote:
> Hi Mathieu,
> 
> > Subject: Re: [PATCH V7 6/7] remoteproc: imx_rproc: request mbox channel
> > later
> > 
> > On Fri, Oct 14, 2022 at 11:10:36AM +0800, Peng Fan (OSS) wrote:
> > > From: Peng Fan <peng.fan@nxp.com>
> > >
> > > It is possible that when remote processor crash, the communication
> > > channel will be broken with garbage value in mailbox, such as when
> > > Linux is issuing a message through mailbox, remote processor crashes,
> > > we need free & rebuild the mailbox channels to make sure no garbage
> > > value in mailbox channels.
> > >
> > > So move the request/free to start/stop for managing remote procesosr
> > > in Linux, move to attach/detach for remote processor is out of control
> > > of Linux.
> > >
> > > Previous, we just request mbox when attach for CM4 boot early before
> > > Linux, but if mbox defer probe, remoteproc core will do resource
> > > cleanup and corrupt resource table for later probe.
> > >
> > > So move request mbox ealier and still keep mbox request when attach
> > > for self recovery case, but keep a check when request/free mbox.
> > >
> > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > > ---
> > >  drivers/remoteproc/imx_rproc.c | 39
> > > ++++++++++++++++++++++++++++++++--
> > >  1 file changed, 37 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/remoteproc/imx_rproc.c
> > > b/drivers/remoteproc/imx_rproc.c index 917e6db39572..1183de84a4c0
> > > 100644
> > > --- a/drivers/remoteproc/imx_rproc.c
> > > +++ b/drivers/remoteproc/imx_rproc.c
> > > @@ -84,6 +84,8 @@ struct imx_rproc_mem {
> > >  #define ATT_CORE_MASK   0xffff
> > >  #define ATT_CORE(I)     BIT((I))
> > >
> > > +static int imx_rproc_xtr_mbox_init(struct rproc *rproc); static void
> > > +imx_rproc_free_mbox(struct rproc *rproc);
> > >  static int imx_rproc_detach_pd(struct rproc *rproc);
> > >
> > >  struct imx_rproc {
> > > @@ -357,6 +359,10 @@ static int imx_rproc_start(struct rproc *rproc)
> > >  	struct arm_smccc_res res;
> > >  	int ret;
> > >
> > > +	ret = imx_rproc_xtr_mbox_init(rproc);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > >  	switch (dcfg->method) {
> > >  	case IMX_RPROC_MMIO:
> > >  		ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
> > > dcfg->src_mask, @@ -407,6 +413,8 @@ static int imx_rproc_stop(struct
> > > rproc *rproc)
> > >
> > >  	if (ret)
> > >  		dev_err(dev, "Failed to stop remote core\n");
> > > +	else
> > > +		imx_rproc_free_mbox(rproc);
> > >
> > >  	return ret;
> > >  }
> > > @@ -592,6 +600,22 @@ static void imx_rproc_kick(struct rproc *rproc,
> > > int vqid)
> > >
> > >  static int imx_rproc_attach(struct rproc *rproc)  {
> > > +	return imx_rproc_xtr_mbox_init(rproc); }
> > > +
> > > +static int imx_rproc_detach(struct rproc *rproc) {
> > > +	struct imx_rproc *priv = rproc->priv;
> > > +	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
> > > +
> > > +	if (dcfg->method != IMX_RPROC_SCU_API)
> > > +		return -EOPNOTSUPP;
> > > +
> > > +	if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
> > > +		return -EOPNOTSUPP;
> > > +
> > > +	imx_rproc_free_mbox(rproc);
> > > +
> > >  	return 0;
> > >  }
> > >
> > > @@ -610,6 +634,7 @@ static struct resource_table
> > > *imx_rproc_get_loaded_rsc_table(struct rproc *rproc  static const struct
> > rproc_ops imx_rproc_ops = {
> > >  	.prepare	= imx_rproc_prepare,
> > >  	.attach		= imx_rproc_attach,
> > > +	.detach		= imx_rproc_detach,
> > >  	.start		= imx_rproc_start,
> > >  	.stop		= imx_rproc_stop,
> > >  	.kick		= imx_rproc_kick,
> > > @@ -720,6 +745,9 @@ static int imx_rproc_xtr_mbox_init(struct rproc
> > *rproc)
> > >  	struct device *dev = priv->dev;
> > >  	struct mbox_client *cl;
> > >
> > > +	if (priv->tx_ch && priv->rx_ch)
> > > +		return 0;
> > > +
> > 
> > You did exactly the same things as in V6.  I asked you why this is needed and
> > all you did is point me to the code in _probe(), which I can read on my own.
> > 
> 
> Sorry for not wrote down clear.
> 
> > Again - why is this needed when we know it will be done in start() and
> > attach()?
> 
> start() and attach() not able to handle mbox defer probe. So I add

We are finally at the heart of the problem.  I had to go look at the
implementation of imx_rproc_xtr_mbox_init() to understand that it can return
-EPROBE_DEFER.  Had there been a comment in the code to highlight _why_ the if()
condition is needed, I would have understood right away and all this waste of
time avoided.

> the mbox requesting in probe to handle mbox defer probe, and add
> a check when requesting mbox channel in start/attach. During first
> time attach/start remote core, the imx_rproc_xtr_mbox_init just
> return, because channel requested in probe flow. 
> 
> Since mbox requested in probe, why still add it in start() and attach()?
> It is to support runtime stop and start(M4 is under control of Linux),
> to support runtime detach(only for i.MX8QM/QXP attach recovery,
> m4 out of control from linux) and attach.
> 
> Thanks,
> Peng.
> > 
> > 
> > >  	if (!of_get_property(dev->of_node, "mbox-names", NULL))
> > >  		return 0;
> > >
> > > @@ -749,8 +777,15 @@ static void imx_rproc_free_mbox(struct rproc
> > > *rproc)  {
> > >  	struct imx_rproc *priv = rproc->priv;
> > >
> > > -	mbox_free_channel(priv->tx_ch);
> > > -	mbox_free_channel(priv->rx_ch);
> > > +	if (priv->tx_ch) {
> > > +		mbox_free_channel(priv->tx_ch);
> > > +		priv->tx_ch = NULL;
> > > +	}
> > > +
> > > +	if (priv->rx_ch) {
> > > +		mbox_free_channel(priv->rx_ch);
> > > +		priv->rx_ch = NULL;
> > > +	}
> > >  }
> > >
> > >  static void imx_rproc_put_scu(struct rproc *rproc)
> > > --
> > > 2.37.1
> > >
Peng Fan Oct. 18, 2022, 7:05 a.m. UTC | #4 
> Subject: Re: [PATCH V7 6/7] remoteproc: imx_rproc: request mbox channel
> later
> 
> On Mon, Oct 17, 2022 at 03:13:16AM +0000, Peng Fan wrote:
> > Hi Mathieu,
> >
> > > Subject: Re: [PATCH V7 6/7] remoteproc: imx_rproc: request mbox
> > > channel later
> > >
> > > On Fri, Oct 14, 2022 at 11:10:36AM +0800, Peng Fan (OSS) wrote:
> > > > From: Peng Fan <peng.fan@nxp.com>
> > > >
> > > > It is possible that when remote processor crash, the communication
> > > > channel will be broken with garbage value in mailbox, such as when
> > > > Linux is issuing a message through mailbox, remote processor
> > > > crashes, we need free & rebuild the mailbox channels to make sure
> > > > no garbage value in mailbox channels.
> > > >
> > > > So move the request/free to start/stop for managing remote
> > > > procesosr in Linux, move to attach/detach for remote processor is
> > > > out of control of Linux.
> > > >
> > > > Previous, we just request mbox when attach for CM4 boot early
> > > > before Linux, but if mbox defer probe, remoteproc core will do
> > > > resource cleanup and corrupt resource table for later probe.
> > > >
> > > > So move request mbox ealier and still keep mbox request when
> > > > attach for self recovery case, but keep a check when request/free
> mbox.
> > > >
> > > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > > > ---
> > > >  drivers/remoteproc/imx_rproc.c | 39
> > > > ++++++++++++++++++++++++++++++++--
> > > >  1 file changed, 37 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/drivers/remoteproc/imx_rproc.c
> > > > b/drivers/remoteproc/imx_rproc.c index
> 917e6db39572..1183de84a4c0
> > > > 100644
> > > > --- a/drivers/remoteproc/imx_rproc.c
> > > > +++ b/drivers/remoteproc/imx_rproc.c
> > > > @@ -84,6 +84,8 @@ struct imx_rproc_mem {
> > > >  #define ATT_CORE_MASK   0xffff
> > > >  #define ATT_CORE(I)     BIT((I))
> > > >
> > > > +static int imx_rproc_xtr_mbox_init(struct rproc *rproc); static
> > > > +void imx_rproc_free_mbox(struct rproc *rproc);
> > > >  static int imx_rproc_detach_pd(struct rproc *rproc);
> > > >
> > > >  struct imx_rproc {
> > > > @@ -357,6 +359,10 @@ static int imx_rproc_start(struct rproc *rproc)
> > > >  	struct arm_smccc_res res;
> > > >  	int ret;
> > > >
> > > > +	ret = imx_rproc_xtr_mbox_init(rproc);
> > > > +	if (ret)
> > > > +		return ret;
> > > > +
> > > >  	switch (dcfg->method) {
> > > >  	case IMX_RPROC_MMIO:
> > > >  		ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
> > > > dcfg->src_mask, @@ -407,6 +413,8 @@ static int
> > > > dcfg->imx_rproc_stop(struct
> > > > rproc *rproc)
> > > >
> > > >  	if (ret)
> > > >  		dev_err(dev, "Failed to stop remote core\n");
> > > > +	else
> > > > +		imx_rproc_free_mbox(rproc);
> > > >
> > > >  	return ret;
> > > >  }
> > > > @@ -592,6 +600,22 @@ static void imx_rproc_kick(struct rproc
> > > > *rproc, int vqid)
> > > >
> > > >  static int imx_rproc_attach(struct rproc *rproc)  {
> > > > +	return imx_rproc_xtr_mbox_init(rproc); }
> > > > +
> > > > +static int imx_rproc_detach(struct rproc *rproc) {
> > > > +	struct imx_rproc *priv = rproc->priv;
> > > > +	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
> > > > +
> > > > +	if (dcfg->method != IMX_RPROC_SCU_API)
> > > > +		return -EOPNOTSUPP;
> > > > +
> > > > +	if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
> > > > +		return -EOPNOTSUPP;
> > > > +
> > > > +	imx_rproc_free_mbox(rproc);
> > > > +
> > > >  	return 0;
> > > >  }
> > > >
> > > > @@ -610,6 +634,7 @@ static struct resource_table
> > > > *imx_rproc_get_loaded_rsc_table(struct rproc *rproc  static const
> > > > struct
> > > rproc_ops imx_rproc_ops = {
> > > >  	.prepare	= imx_rproc_prepare,
> > > >  	.attach		= imx_rproc_attach,
> > > > +	.detach		= imx_rproc_detach,
> > > >  	.start		= imx_rproc_start,
> > > >  	.stop		= imx_rproc_stop,
> > > >  	.kick		= imx_rproc_kick,
> > > > @@ -720,6 +745,9 @@ static int imx_rproc_xtr_mbox_init(struct
> > > > rproc
> > > *rproc)
> > > >  	struct device *dev = priv->dev;
> > > >  	struct mbox_client *cl;
> > > >
> > > > +	if (priv->tx_ch && priv->rx_ch)
> > > > +		return 0;
> > > > +
> > >
> > > You did exactly the same things as in V6.  I asked you why this is
> > > needed and all you did is point me to the code in _probe(), which I can
> read on my own.
> > >
> >
> > Sorry for not wrote down clear.
> >
> > > Again - why is this needed when we know it will be done in start()
> > > and attach()?
> >
> > start() and attach() not able to handle mbox defer probe. So I add
> 
> We are finally at the heart of the problem.  I had to go look at the
> implementation of imx_rproc_xtr_mbox_init() to understand that it can
> return -EPROBE_DEFER.  Had there been a comment in the code to highlight
> _why_ the if() condition is needed, I would have understood right away and
> all this waste of time avoided.

My bad. I could add comment in V8 if no major comments after you review.
Thanks for your time.

Thanks,
Peng.
> 
> > the mbox requesting in probe to handle mbox defer probe, and add a
> > check when requesting mbox channel in start/attach. During first time
> > attach/start remote core, the imx_rproc_xtr_mbox_init just return,
> > because channel requested in probe flow.
> >
> > Since mbox requested in probe, why still add it in start() and attach()?
> > It is to support runtime stop and start(M4 is under control of Linux),
> > to support runtime detach(only for i.MX8QM/QXP attach recovery,
> > m4 out of control from linux) and attach.
> >
> > Thanks,
> > Peng.
> > >
> > >
> > > >  	if (!of_get_property(dev->of_node, "mbox-names", NULL))
> > > >  		return 0;
> > > >
> > > > @@ -749,8 +777,15 @@ static void imx_rproc_free_mbox(struct rproc
> > > > *rproc)  {
> > > >  	struct imx_rproc *priv = rproc->priv;
> > > >
> > > > -	mbox_free_channel(priv->tx_ch);
> > > > -	mbox_free_channel(priv->rx_ch);
> > > > +	if (priv->tx_ch) {
> > > > +		mbox_free_channel(priv->tx_ch);
> > > > +		priv->tx_ch = NULL;
> > > > +	}
> > > > +
> > > > +	if (priv->rx_ch) {
> > > > +		mbox_free_channel(priv->rx_ch);
> > > > +		priv->rx_ch = NULL;
> > > > +	}
> > > >  }
> > > >
> > > >  static void imx_rproc_put_scu(struct rproc *rproc)
> > > > --
> > > > 2.37.1
> > > >
diff mbox series

Patch

diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
index 917e6db39572..1183de84a4c0 100644
--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c
@@ -84,6 +84,8 @@  struct imx_rproc_mem {
 #define ATT_CORE_MASK   0xffff
 #define ATT_CORE(I)     BIT((I))
 
+static int imx_rproc_xtr_mbox_init(struct rproc *rproc);
+static void imx_rproc_free_mbox(struct rproc *rproc);
 static int imx_rproc_detach_pd(struct rproc *rproc);
 
 struct imx_rproc {
@@ -357,6 +359,10 @@  static int imx_rproc_start(struct rproc *rproc)
 	struct arm_smccc_res res;
 	int ret;
 
+	ret = imx_rproc_xtr_mbox_init(rproc);
+	if (ret)
+		return ret;
+
 	switch (dcfg->method) {
 	case IMX_RPROC_MMIO:
 		ret = regmap_update_bits(priv->regmap, dcfg->src_reg, dcfg->src_mask,
@@ -407,6 +413,8 @@  static int imx_rproc_stop(struct rproc *rproc)
 
 	if (ret)
 		dev_err(dev, "Failed to stop remote core\n");
+	else
+		imx_rproc_free_mbox(rproc);
 
 	return ret;
 }
@@ -592,6 +600,22 @@  static void imx_rproc_kick(struct rproc *rproc, int vqid)
 
 static int imx_rproc_attach(struct rproc *rproc)
 {
+	return imx_rproc_xtr_mbox_init(rproc);
+}
+
+static int imx_rproc_detach(struct rproc *rproc)
+{
+	struct imx_rproc *priv = rproc->priv;
+	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
+
+	if (dcfg->method != IMX_RPROC_SCU_API)
+		return -EOPNOTSUPP;
+
+	if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
+		return -EOPNOTSUPP;
+
+	imx_rproc_free_mbox(rproc);
+
 	return 0;
 }
 
@@ -610,6 +634,7 @@  static struct resource_table *imx_rproc_get_loaded_rsc_table(struct rproc *rproc
 static const struct rproc_ops imx_rproc_ops = {
 	.prepare	= imx_rproc_prepare,
 	.attach		= imx_rproc_attach,
+	.detach		= imx_rproc_detach,
 	.start		= imx_rproc_start,
 	.stop		= imx_rproc_stop,
 	.kick		= imx_rproc_kick,
@@ -720,6 +745,9 @@  static int imx_rproc_xtr_mbox_init(struct rproc *rproc)
 	struct device *dev = priv->dev;
 	struct mbox_client *cl;
 
+	if (priv->tx_ch && priv->rx_ch)
+		return 0;
+
 	if (!of_get_property(dev->of_node, "mbox-names", NULL))
 		return 0;
 
@@ -749,8 +777,15 @@  static void imx_rproc_free_mbox(struct rproc *rproc)
 {
 	struct imx_rproc *priv = rproc->priv;
 
-	mbox_free_channel(priv->tx_ch);
-	mbox_free_channel(priv->rx_ch);
+	if (priv->tx_ch) {
+		mbox_free_channel(priv->tx_ch);
+		priv->tx_ch = NULL;
+	}
+
+	if (priv->rx_ch) {
+		mbox_free_channel(priv->rx_ch);
+		priv->rx_ch = NULL;
+	}
 }
 
 static void imx_rproc_put_scu(struct rproc *rproc)