Reviewed the patch & it looks good. Just to confirm, this patch tries to address the case of a tiny window of transition, i.e. from the 1st field (last half line) to 2nd field (first half line).
Reviewed-by: "Akash Goel <[email protected]>" On Tue, Apr 29, 2014 at 4:05 PM, <[email protected]> wrote: > From: Ville Syrjälä <[email protected]> > > In interlaced modes, the pixel counter counts all pixels, > so one field will have htotal more pixels. In order to avoid > the reported position from jumping backwards when the pixel > counter is beyond the length of the shorter field, just > clamp the position the length of the shorter field. This > matches how the scanline counter based position works since > the scanline counter doesn't count the two half lines. > > Signed-off-by: Ville Syrjälä <[email protected]> > --- > drivers/gpu/drm/i915/i915_irq.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_irq.c > b/drivers/gpu/drm/i915/i915_irq.c > index 7e0d577..64cd888 100644 > --- a/drivers/gpu/drm/i915/i915_irq.c > +++ b/drivers/gpu/drm/i915/i915_irq.c > @@ -844,6 +844,18 @@ static int i915_get_crtc_scanoutpos(struct drm_device > *dev, int pipe, > vtotal *= htotal; > > /* > + * In interlaced modes, the pixel counter counts all > pixels, > + * so one field will have htotal more pixels. In order to > avoid > + * the reported position from jumping backwards when the > pixel > + * counter is beyond the length of the shorter field, just > + * clamp the position the length of the shorter field. This > + * matches how the scanline counter based position works > since > + * the scanline counter doesn't count the two half lines. > + */ > + if (position >= vtotal) > + position = vtotal - 1; > + > + /* > * Start of vblank interrupt is triggered at start of > hsync, > * just prior to the first active line of vblank. However > we > * consider lines to start at the leading edge of > horizontal > -- > 1.8.3.2 > > _______________________________________________ > Intel-gfx mailing list > [email protected] > http://lists.freedesktop.org/mailman/listinfo/intel-gfx >
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