2020-07-08 17:51:16

by Maxime Ripard

Subject: [PATCH v4 24/78] drm/vc4: hvs: Make sure our channel is reset

In order to clear our intermediate FIFOs that might end up with a stale
pixel, let's make sure our FIFO channel is reset everytime our channel is
setup.

Signed-off-by: Maxime Ripard <[email protected]>
---
drivers/gpu/drm/vc4/vc4_hvs.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index c7de77afbf0a..64b9d72471ef 100644
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -205,6 +205,10 @@ static int vc4_hvs_init_channel(struct vc4_dev *vc4, struct drm_crtc *crtc,
u32 dispbkgndx;
u32 dispctrl;

+ HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
+ HVS_WRITE(SCALER_DISPCTRLX(chan), SCALER_DISPCTRLX_RESET);
+ HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
+
/* Turn on the scaler, which will wait for vstart to start
* compositing.
* When feeding the transposer, we should operate in oneshot
--
git-series 0.9.1

2020-07-28 10:39:12

by Dave Stevenson

Subject: Re: [PATCH v4 24/78] drm/vc4: hvs: Make sure our channel is reset

Hi Maxime

On Wed, 8 Jul 2020 at 18:43, Maxime Ripard <[email protected]> wrote:
>
> In order to clear our intermediate FIFOs that might end up with a stale
> pixel, let's make sure our FIFO channel is reset everytime our channel is
> setup.

Minor nit pick: s/everytime/every time

> Signed-off-by: Maxime Ripard <[email protected]>

Reviewed-by: Dave Stevenson <[email protected]>

> ---
> drivers/gpu/drm/vc4/vc4_hvs.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
> index c7de77afbf0a..64b9d72471ef 100644
> --- a/drivers/gpu/drm/vc4/vc4_hvs.c
> +++ b/drivers/gpu/drm/vc4/vc4_hvs.c
> @@ -205,6 +205,10 @@ static int vc4_hvs_init_channel(struct vc4_dev *vc4, struct drm_crtc *crtc,
> u32 dispbkgndx;
> u32 dispctrl;
>
> + HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
> + HVS_WRITE(SCALER_DISPCTRLX(chan), SCALER_DISPCTRLX_RESET);
> + HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
> +
> /* Turn on the scaler, which will wait for vstart to start
> * compositing.
> * When feeding the transposer, we should operate in oneshot
> --
> git-series 0.9.1