2020-07-08 17:46:10

by Maxime Ripard

Subject: [PATCH v4 70/78] drm/vc4: hdmi: Always recenter the HDMI FIFO

In order to avoid a pixel getting stuck in an unflushable FIFO, we need to
recenter the FIFO every time we're doing a modeset and not only if we're
connected to an HDMI monitor.

Signed-off-by: Maxime Ripard <[email protected]>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 46 +++++++++++++++++++----------------
1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 4058985940e6..00592c1ada73 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -425,6 +425,30 @@ static void vc4_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
(hsync_pos ? 0 : VC4_HD_VID_CTL_HSYNC_LOW));
}

+static void vc4_hdmi_recenter_fifo(struct vc4_hdmi *vc4_hdmi)
+{
+ u32 drift;
+ int ret;
+
+ drift = HDMI_READ(HDMI_FIFO_CTL);
+ drift &= VC4_HDMI_FIFO_VALID_WRITE_MASK;
+
+ HDMI_WRITE(HDMI_FIFO_CTL,
+ drift & ~VC4_HDMI_FIFO_CTL_RECENTER);
+ HDMI_WRITE(HDMI_FIFO_CTL,
+ drift | VC4_HDMI_FIFO_CTL_RECENTER);
+ usleep_range(1000, 1100);
+ HDMI_WRITE(HDMI_FIFO_CTL,
+ drift & ~VC4_HDMI_FIFO_CTL_RECENTER);
+ HDMI_WRITE(HDMI_FIFO_CTL,
+ drift | VC4_HDMI_FIFO_CTL_RECENTER);
+
+ ret = wait_for(HDMI_READ(HDMI_FIFO_CTL) &
+ VC4_HDMI_FIFO_CTL_RECENTER_DONE, 1);
+ WARN_ONCE(ret, "Timeout waiting for "
+ "VC4_HDMI_FIFO_CTL_RECENTER_DONE");
+}
+
static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
{
struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
@@ -543,8 +567,6 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
}

if (vc4_encoder->hdmi_monitor) {
- u32 drift;
-
WARN_ON(!(HDMI_READ(HDMI_SCHEDULER_CONTROL) &
VC4_HDMI_SCHEDULER_CONTROL_HDMI_ACTIVE));
HDMI_WRITE(HDMI_SCHEDULER_CONTROL,
@@ -555,25 +577,9 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
VC4_HDMI_RAM_PACKET_ENABLE);

vc4_hdmi_set_infoframes(encoder);
-
- drift = HDMI_READ(HDMI_FIFO_CTL);
- drift &= VC4_HDMI_FIFO_VALID_WRITE_MASK;
-
- HDMI_WRITE(HDMI_FIFO_CTL,
- drift & ~VC4_HDMI_FIFO_CTL_RECENTER);
- HDMI_WRITE(HDMI_FIFO_CTL,
- drift | VC4_HDMI_FIFO_CTL_RECENTER);
- usleep_range(1000, 1100);
- HDMI_WRITE(HDMI_FIFO_CTL,
- drift & ~VC4_HDMI_FIFO_CTL_RECENTER);
- HDMI_WRITE(HDMI_FIFO_CTL,
- drift | VC4_HDMI_FIFO_CTL_RECENTER);
-
- ret = wait_for(HDMI_READ(HDMI_FIFO_CTL) &
- VC4_HDMI_FIFO_CTL_RECENTER_DONE, 1);
- WARN_ONCE(ret, "Timeout waiting for "
- "VC4_HDMI_FIFO_CTL_RECENTER_DONE");
}
+
+ vc4_hdmi_recenter_fifo(vc4_hdmi);
}

static enum drm_mode_status
--
git-series 0.9.1

2020-07-28 15:05:41

by Dave Stevenson

Subject: Re: [PATCH v4 70/78] drm/vc4: hdmi: Always recenter the HDMI FIFO

Hi Maxime

On Wed, 8 Jul 2020 at 18:44, Maxime Ripard <[email protected]> wrote:
>
> In order to avoid a pixel getting stuck in an unflushable FIFO, we need to
> recenter the FIFO every time we're doing a modeset and not only if we're
> connected to an HDMI monitor.
>
> Signed-off-by: Maxime Ripard <[email protected]>

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

> ---
> drivers/gpu/drm/vc4/vc4_hdmi.c | 46 +++++++++++++++++++----------------
> 1 file changed, 26 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 4058985940e6..00592c1ada73 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -425,6 +425,30 @@ static void vc4_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
> (hsync_pos ? 0 : VC4_HD_VID_CTL_HSYNC_LOW));
> }
>
> +static void vc4_hdmi_recenter_fifo(struct vc4_hdmi *vc4_hdmi)
> +{
> + u32 drift;
> + int ret;
> +
> + drift = HDMI_READ(HDMI_FIFO_CTL);
> + drift &= VC4_HDMI_FIFO_VALID_WRITE_MASK;
> +
> + HDMI_WRITE(HDMI_FIFO_CTL,
> + drift & ~VC4_HDMI_FIFO_CTL_RECENTER);
> + HDMI_WRITE(HDMI_FIFO_CTL,
> + drift | VC4_HDMI_FIFO_CTL_RECENTER);
> + usleep_range(1000, 1100);
> + HDMI_WRITE(HDMI_FIFO_CTL,
> + drift & ~VC4_HDMI_FIFO_CTL_RECENTER);
> + HDMI_WRITE(HDMI_FIFO_CTL,
> + drift | VC4_HDMI_FIFO_CTL_RECENTER);
> +
> + ret = wait_for(HDMI_READ(HDMI_FIFO_CTL) &
> + VC4_HDMI_FIFO_CTL_RECENTER_DONE, 1);
> + WARN_ONCE(ret, "Timeout waiting for "
> + "VC4_HDMI_FIFO_CTL_RECENTER_DONE");
> +}
> +
> static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
> {
> struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
> @@ -543,8 +567,6 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
> }
>
> if (vc4_encoder->hdmi_monitor) {
> - u32 drift;
> -
> WARN_ON(!(HDMI_READ(HDMI_SCHEDULER_CONTROL) &
> VC4_HDMI_SCHEDULER_CONTROL_HDMI_ACTIVE));
> HDMI_WRITE(HDMI_SCHEDULER_CONTROL,
> @@ -555,25 +577,9 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
> VC4_HDMI_RAM_PACKET_ENABLE);
>
> vc4_hdmi_set_infoframes(encoder);
> -
> - drift = HDMI_READ(HDMI_FIFO_CTL);
> - drift &= VC4_HDMI_FIFO_VALID_WRITE_MASK;
> -
> - HDMI_WRITE(HDMI_FIFO_CTL,
> - drift & ~VC4_HDMI_FIFO_CTL_RECENTER);
> - HDMI_WRITE(HDMI_FIFO_CTL,
> - drift | VC4_HDMI_FIFO_CTL_RECENTER);
> - usleep_range(1000, 1100);
> - HDMI_WRITE(HDMI_FIFO_CTL,
> - drift & ~VC4_HDMI_FIFO_CTL_RECENTER);
> - HDMI_WRITE(HDMI_FIFO_CTL,
> - drift | VC4_HDMI_FIFO_CTL_RECENTER);
> -
> - ret = wait_for(HDMI_READ(HDMI_FIFO_CTL) &
> - VC4_HDMI_FIFO_CTL_RECENTER_DONE, 1);
> - WARN_ONCE(ret, "Timeout waiting for "
> - "VC4_HDMI_FIFO_CTL_RECENTER_DONE");
> }
> +
> + vc4_hdmi_recenter_fifo(vc4_hdmi);
> }
>
> static enum drm_mode_status
> --
> git-series 0.9.1