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drm/i915: Fix scanoutpos calculations 

The reported scanout position must be relative to the end of vblank.
Currently we manage to fumble that in a few ways.

First we don't consider the case when vtotal != vbl_end. While that
isn't very common (happens maybe only w/ old panel fitting hardware),
we can fix it easily enough.

The second issue is that on pre-CTG hardware we convert the pixel count
to horizontal/vertical components at the very beginning, and then forget
to adjust the horizontal component to be relative to vbl_end. So instead
we should keep our numbers in the pixel count domain while we're
adjusting the position to be relative to vbl_end. Then when we do the
conversion in the end, both vertical _and_ horizontal components will
come out correct.

v2: Change position to int from u32 to avoid sign issues

Cc: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: mario.kleiner.de@gmail.com
Tested-by: mario.kleiner.de@gmail.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ville Syrjälä 2013-10-11 19:10:32 +03:00 committed by Daniel Vetter
parent c2baf4b709
commit 3aa18df8f2
1 changed files with 25 additions and 14 deletions
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39
drivers/gpu/drm/i915/i915_irq.c
View File

@ -599,7 +599,7 @@ static int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
const struct drm_display_mode *mode = &intel_crtc->config.adjusted_mode;
u32 position;
int position;
int vbl_start, vbl_end, htotal, vtotal;
bool in_vbl = true;
int ret = 0;
@ -621,13 +621,7 @@ static int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
/* No obvious pixelcount register. Only query vertical
* scanout position from Display scan line register.
*/
position = I915_READ(PIPEDSL(pipe));
/* Decode into vertical scanout position. Don't have
* horizontal scanout position.
*/
*vpos = position & 0x1fff;
*hpos = 0;
position = I915_READ(PIPEDSL(pipe)) & 0x1fff;
} else {
/* Have access to pixelcount since start of frame.
* We can split this into vertical and horizontal
@ -635,16 +629,33 @@ static int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
*/
position = (I915_READ(PIPEFRAMEPIXEL(pipe)) & PIPE_PIXEL_MASK) >> PIPE_PIXEL_SHIFT;
/* convert to pixel counts */
vbl_start *= htotal;
vbl_end *= htotal;
vtotal *= htotal;
}
in_vbl = position >= vbl_start && position < vbl_end;
/*
* While in vblank, position will be negative
* counting up towards 0 at vbl_end. And outside
* vblank, position will be positive counting
* up since vbl_end.
*/
if (position >= vbl_start)
position -= vbl_end;
else
position += vtotal - vbl_end;
if (IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5) {
*vpos = position;
*hpos = 0;
} else {
*vpos = position / htotal;
*hpos = position - (*vpos * htotal);
}
in_vbl = *vpos >= vbl_start && *vpos < vbl_end;
/* Inside "upper part" of vblank area? Apply corrective offset: */
if (in_vbl && (*vpos >= vbl_start))
*vpos = *vpos - vtotal;
/* In vblank? */
if (in_vbl)
ret |= DRM_SCANOUTPOS_INVBL;