diff mbox series

[v11,3/9] drm/mediatek: add RDMA fifo size error handle

Message ID 20210128072802.830971-4-hsinyi@chromium.org (mailing list archive)
State New
Headers show
Series drm/mediatek: add support for mediatek SOC MT8183 | expand

Commit Message

Hsin-Yi Wang Jan. 28, 2021, 7:27 a.m. UTC
From: Yongqiang Niu <yongqiang.niu@mediatek.com>

This patch add RDMA fifo size error handle
rdma fifo size will not always bigger than the calculated threshold
if that case happened, we need set fifo size as the threshold

Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

CK Hu Jan. 28, 2021, 7:50 a.m. UTC | #1
Hi, Hsin-Yi:

On Thu, 2021-01-28 at 15:27 +0800, Hsin-Yi Wang wrote:
> From: Yongqiang Niu <yongqiang.niu@mediatek.com>
> 
> This patch add RDMA fifo size error handle
> rdma fifo size will not always bigger than the calculated threshold
> if that case happened, we need set fifo size as the threshold
> 
> Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> index b84004394970f..04b9542010b00 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> @@ -168,6 +168,10 @@ void mtk_rdma_config(struct device *dev, unsigned int width,
>  	 * account for blanking, and with a pixel depth of 4 bytes:
>  	 */
>  	threshold = width * height * vrefresh * 4 * 7 / 1000000;
> +
> +	if (threshold > rdma_fifo_size)
> +		threshold = rdma_fifo_size;
> +

Please see the discussion in [1].

[1]
https://patchwork.kernel.org/project/linux-mediatek/patch/1607591262-21736-6-git-send-email-yongqiang.niu@mediatek.com/

Regards,
CK

>  	reg = RDMA_FIFO_UNDERFLOW_EN |
>  	      RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) |
>  	      RDMA_OUTPUT_VALID_FIFO_THRESHOLD(threshold);
Hsin-Yi Wang Jan. 28, 2021, 11:12 a.m. UTC | #2
On Thu, Jan 28, 2021 at 3:52 PM CK Hu <ck.hu@mediatek.com> wrote:
>
> Hi, Hsin-Yi:
>
> On Thu, 2021-01-28 at 15:27 +0800, Hsin-Yi Wang wrote:
> > From: Yongqiang Niu <yongqiang.niu@mediatek.com>
> >
> > This patch add RDMA fifo size error handle
> > rdma fifo size will not always bigger than the calculated threshold
> > if that case happened, we need set fifo size as the threshold
> >
> > Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
> > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> > index b84004394970f..04b9542010b00 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> > @@ -168,6 +168,10 @@ void mtk_rdma_config(struct device *dev, unsigned int width,
> >        * account for blanking, and with a pixel depth of 4 bytes:
> >        */
> >       threshold = width * height * vrefresh * 4 * 7 / 1000000;
> > +
> > +     if (threshold > rdma_fifo_size)
> > +             threshold = rdma_fifo_size;
> > +
>
> Please see the discussion in [1].
>
> [1]
> https://patchwork.kernel.org/project/linux-mediatek/patch/1607591262-21736-6-git-send-email-yongqiang.niu@mediatek.com/
>
> Regards,
> CK
>

Hi CK,

Even if we set threshold to
threshold = RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) * width * height *
vrefresh / 2 / MAX_WIDTH / MAX_HEIGHT / MAX_VREFRESH;

I'm not sure what value MAX_WIDTH, MAX_HEIGHT, and MAX_VREFRESH should
set to for each SoC.
Since there's no conclusion yet, I'll drop this patch in the series,
as this seems not an mt8183 specific fix.


> >       reg = RDMA_FIFO_UNDERFLOW_EN |
> >             RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) |
> >             RDMA_OUTPUT_VALID_FIFO_THRESHOLD(threshold);
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
index b84004394970f..04b9542010b00 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
@@ -168,6 +168,10 @@  void mtk_rdma_config(struct device *dev, unsigned int width,
 	 * account for blanking, and with a pixel depth of 4 bytes:
 	 */
 	threshold = width * height * vrefresh * 4 * 7 / 1000000;
+
+	if (threshold > rdma_fifo_size)
+		threshold = rdma_fifo_size;
+
 	reg = RDMA_FIFO_UNDERFLOW_EN |
 	      RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) |
 	      RDMA_OUTPUT_VALID_FIFO_THRESHOLD(threshold);