[v4,70/78] drm/vc4: hdmi: Always recenter the HDMI FIFO
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Message ID 12499869afccd632b222eec328a6352111472986.1594230107.git-series.maxime@cerno.tech
State New
Headers show
Series
  • drm/vc4: Support BCM2711 Display Pipeline
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Commit Message

Maxime Ripard July 8, 2020, 5:42 p.m. UTC
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 <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 46 +++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 20 deletions(-)

Comments

Dave Stevenson July 28, 2020, 3:03 p.m. UTC | #1
Hi Maxime

On Wed, 8 Jul 2020 at 18:44, Maxime Ripard <maxime@cerno.tech> 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 <maxime@cerno.tech>

Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

> ---
>  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

Patch
diff mbox series

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