diff mbox series

[3/4] drm: xlnx: zynqmp_dpsub: Don't generate vblank in live mode

Message ID 20240112234222.913138-4-anatoliy.klymenko@amd.com
State New
Headers
Series Fixing live video input in ZynqMP DPSUB |

Commit Message

Klymenko, Anatoliy Jan. 12, 2024, 11:42 p.m. UTC 
  Filter out status register against interrupts' mask.
Some events are being reported via DP status register, even if
corresponding interrupts have been disabled. Avoid processing
of such events in interrupt handler context.

Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
---
 drivers/gpu/drm/xlnx/zynqmp_dp.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Comments

Tomi Valkeinen Jan. 17, 2024, 2:20 p.m. UTC | #1 
On 13/01/2024 01:42, Anatoliy Klymenko wrote:
> Filter out status register against interrupts' mask.
> Some events are being reported via DP status register, even if
> corresponding interrupts have been disabled. Avoid processing
> of such events in interrupt handler context.

The subject talks about vblank and live mode, the the description 
doesn't. Can you elaborate in the desc a bit about when this is an issue 
and why it wasn't before?

> Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
> ---
>   drivers/gpu/drm/xlnx/zynqmp_dp.c | 11 +++++++++--
>   1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> index d60b7431603f..571c5dbc97e5 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> @@ -1624,8 +1624,16 @@ static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
>   	u32 status, mask;
>   
>   	status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
> +	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
>   	mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
> -	if (!(status & ~mask))
> +
> +	/*
> +	 * Status register may report some events, which corresponding interrupts
> +	 * have been disabled. Filter out those events against interrupts' mask.
> +	 */
> +	status &= ~mask;
> +
> +	if (!status)
>   		return IRQ_NONE;
>   
>   	/* dbg for diagnostic, but not much that the driver can do */
> @@ -1634,7 +1642,6 @@ static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
>   	if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
>   		dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
>   
> -	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
>   
>   	if (status & ZYNQMP_DP_INT_VBLANK_START)
>   		zynqmp_dpsub_drm_handle_vblank(dp->dpsub);

Moving the zynqmp_dp_write() is not related to this fix, is it? I think 
it should be in a separate patch.

  Tomi
diff mbox series

Patch

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index d60b7431603f..571c5dbc97e5 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -1624,8 +1624,16 @@  static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
 	u32 status, mask;
 
 	status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
+	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
 	mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
-	if (!(status & ~mask))
+
+	/*
+	 * Status register may report some events, which corresponding interrupts
+	 * have been disabled. Filter out those events against interrupts' mask.
+	 */
+	status &= ~mask;
+
+	if (!status)
 		return IRQ_NONE;
 
 	/* dbg for diagnostic, but not much that the driver can do */
@@ -1634,7 +1642,6 @@  static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
 	if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
 		dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
 
-	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
 
 	if (status & ZYNQMP_DP_INT_VBLANK_START)
 		zynqmp_dpsub_drm_handle_vblank(dp->dpsub);