Re: [PATCH v3 3/5] drm: xlnx: zynqmp_dpsub: Clear status register ASAP

From: Laurent Pinchart
Date: Mon Feb 05 2024 - 02:34:04 EST


Hi Anatoliy,

Thank you for the patch.

On Tue, Jan 23, 2024 at 06:54:00PM -0800, Anatoliy Klymenko wrote:
> Clear status register as soon as we read it.
>
> Addressing comments from
> https://lore.kernel.org/dri-devel/beb551c7-bb7e-4cd0-b166-e9aad90c4620@xxxxxxxxxxxxxxxx/
>
> Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@xxxxxxx>
> ---
> drivers/gpu/drm/xlnx/zynqmp_dp.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> index d60b7431603f..5a3335e1fffa 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> @@ -1624,6 +1624,8 @@ static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
> u32 status, mask;
>
> status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
> + /* clear status register as soon as we read it */

I don't think a comment is strictly required, but I don't mind it.

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

> + zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
> mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
> if (!(status & ~mask))
> return IRQ_NONE;
> @@ -1634,8 +1636,6 @@ 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);
>

--
Regards,

Laurent Pinchart