diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_irq.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 2043276..cfa4d36 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -915,6 +915,18 @@ 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 |
