diff options
| author | Dom Cobley <popcornmix@gmail.com> | 2021-01-21 11:57:58 +0100 |
|---|---|---|
| committer | Maxime Ripard <maxime@cerno.tech> | 2021-01-25 11:52:59 +0100 |
| commit | 78e5330329ee206d6aa4593a90320fd837f7966e (patch) | |
| tree | bca73da8a6ec881347bd6851056413561a2e57a1 /drivers/gpu/drm/vc4/vc4_hvs.c | |
| parent | a37eef63bc9e16e06361b539e528058146af80ab (diff) | |
drm/vc4: Correct lbm size and calculation
LBM base address is measured in units of pixels per cycle.
That is 4 for 2711 (hvs5) and 2 for 2708.
We are wasting 75% of lbm by indexing without the scaling.
But we were also using too high a size for the lbm resulting
in partial corruption (right hand side) of vertically
scaled images, usually at 4K or lower resolutions with more layers.
The physical RAM of LBM on 2711 is 8 * 1920 * 16 * 12-bit
(pixels are stored 12-bits per component regardless of format).
The LBM address indexes work in units of pixels per clock,
so for 4 pixels per clock that means we have 32 * 1920 = 60K
Fixes: c54619b0bfb3 ("drm/vc4: Add support for the BCM2711 HVS5")
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Tested-By: Lucas Nussbaum <lucas@debian.org>
Tested-By: Ryutaroh Matsumoto <ryutaroh@ict.e.titech.ac.jp>
Link: https://patchwork.freedesktop.org/patch/msgid/20210121105759.1262699-1-maxime@cerno.tech
Diffstat (limited to 'drivers/gpu/drm/vc4/vc4_hvs.c')
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_hvs.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c index cccd341e5d67..3b722252d1fb 100644 --- a/drivers/gpu/drm/vc4/vc4_hvs.c +++ b/drivers/gpu/drm/vc4/vc4_hvs.c @@ -620,11 +620,11 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data) * for now we just allocate globally. */ if (!hvs->hvs5) - /* 96kB */ - drm_mm_init(&hvs->lbm_mm, 0, 96 * 1024); + /* 48k words of 2x12-bit pixels */ + drm_mm_init(&hvs->lbm_mm, 0, 48 * 1024); else - /* 70k words */ - drm_mm_init(&hvs->lbm_mm, 0, 70 * 2 * 1024); + /* 60k words of 4x12-bit pixels */ + drm_mm_init(&hvs->lbm_mm, 0, 60 * 1024); /* Upload filter kernels. We only have the one for now, so we * keep it around for the lifetime of the driver. |