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

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
Cc: maarten.lankhorst@linux.intel.com, mripard@kernel.org,
	tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch,
	michal.simek@amd.com, dri-devel@lists.freedesktop.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/5] drm: xlnx: zynqmp_dpsub: Clear status register ASAP
Date: Mon, 5 Feb 2024 09:33:57 +0200	[thread overview]
Message-ID: <20240205073357.GF6804@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20240124025402.373620-4-anatoliy.klymenko@amd.com>

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@ideasonboard.com/
> 
> Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
> ---
>  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@ideasonboard.com>

> +	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

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