[PATCH] radeon: Set DESKTOP_HEIGHT register to the framebuffer (not mode) height.

[Alex Deucher]

2012/2/1 Michel Dänzer <michel at daenzer.net>:
> From: Michel Dänzer <michel.daenzer at amd.com>
>
> The value of this register is transferred to the V_COUNTER register at the
> beginning of vertical blank. V_COUNTER is the reference for VLINE waits and
> goes from VIEWPORT_Y_START to VIEWPORT_Y_START+VIEWPORT_HEIGHT during scanout,
> so if VIEWPORT_Y_START is not 0, V_COUNTER actually went backwards at the
> beginning of vertical blank, and VLINE waits excluding the whole scanout area
> could never finish (possibly only if VIEWPORT_Y_START is larger than the length
> of vertical blank in scanlines). Setting DESKTOP_HEIGHT to the framebuffer
> height should prevent this for any kind of VLINE wait.
>
> Fixes https://bugs.freedesktop.org/show_bug.cgi?id=45329 .
>
> CC: stable at vger.kernel.org
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>
> Maybe we should also check/clamp the VLINE ranges from userspace?
>
>  drivers/gpu/drm/radeon/atombios_crtc.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 0fda830..c54efd4 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -1189,7 +1189,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
>        WREG32(EVERGREEN_GRPH_ENABLE + radeon_crtc->crtc_offset, 1);
>
>        WREG32(EVERGREEN_DESKTOP_HEIGHT + radeon_crtc->crtc_offset,
> -              crtc->mode.vdisplay);
> +              target_fb->height);
>        x &= ~3;
>        y &= ~1;
>        WREG32(EVERGREEN_VIEWPORT_START + radeon_crtc->crtc_offset,
> @@ -1358,7 +1358,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
>        WREG32(AVIVO_D1GRPH_ENABLE + radeon_crtc->crtc_offset, 1);
>
>        WREG32(AVIVO_D1MODE_DESKTOP_HEIGHT + radeon_crtc->crtc_offset,
> -              crtc->mode.vdisplay);
> +              target_fb->height);
>        x &= ~3;
>        y &= ~1;
>        WREG32(AVIVO_D1MODE_VIEWPORT_START + radeon_crtc->crtc_offset,
> --
> 1.7.8.3
>
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