Re: [PATCH v3 040/105] drm/vc4: crtc: Turn pixelvalve reset into a function

[Eric Anholt]

On Wed, May 27, 2020 at 8:50 AM Maxime Ripard  wrote:
>
> The driver resets the pixelvalve FIFO in a number of occurences without
> always using the same sequence.
>
> Since this will be critical for BCM2711, let's move that sequence to a
> function so that we are consistent.
>
> Signed-off-by: Maxime Ripard 

Patch 34-40 also r-b.

Going to take a little break, this is a lot to try to process at once.
Hopefully you can merge reviewed stuff to drm-misc and shorten the
series.

[PATCH v3 040/105] drm/vc4: crtc: Turn pixelvalve reset into a function

[Maxime Ripard]

The driver resets the pixelvalve FIFO in a number of occurences without
always using the same sequence.

Since this will be critical for BCM2711, let's move that sequence to a
function so that we are consistent.

Signed-off-by: Maxime Ripard 
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 20 +---
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 9ec345254808..983ae476c203 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -308,6 +308,15 @@ static struct drm_encoder *vc4_get_crtc_encoder(struct 
drm_crtc *crtc)
return NULL;
 }
 
+static void vc4_crtc_pixelvalve_reset(struct drm_crtc *crtc)
+{
+   struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+
+   /* The PV needs to be disabled before it can be flushed */
+   CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) & ~PV_CONTROL_EN);
+   CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | PV_CONTROL_FIFO_CLR);
+}
+
 static void vc4_crtc_config_pv(struct drm_crtc *crtc)
 {
struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc);
@@ -322,10 +331,7 @@ static void vc4_crtc_config_pv(struct drm_crtc *crtc)
u32 format = is_dsi ? PV_CONTROL_FORMAT_DSIV_24 : PV_CONTROL_FORMAT_24;
u8 ppc = vc4_crtc->data->pixels_per_clock;
 
-   /* Reset the PV fifo. */
-   CRTC_WRITE(PV_CONTROL, 0);
-   CRTC_WRITE(PV_CONTROL, PV_CONTROL_FIFO_CLR | PV_CONTROL_EN);
-   CRTC_WRITE(PV_CONTROL, 0);
+   vc4_crtc_pixelvalve_reset(crtc);
 
CRTC_WRITE(PV_HORZA,
   VC4_SET_FIELD((mode->htotal - mode->hsync_end) * pixel_rep / 
ppc,
@@ -573,9 +579,9 @@ static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,
 
require_hvs_enabled(dev);
 
-   /* Reset the PV fifo. */
-   CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) |
-  PV_CONTROL_FIFO_CLR | PV_CONTROL_EN);
+   vc4_crtc_pixelvalve_reset(crtc);
+
+   CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | PV_CONTROL_EN);
 
/* Enable vblank irq handling before crtc is started otherwise
 * drm_crtc_get_vblank() fails in vc4_crtc_update_dlist().
-- 
git-series 0.9.1