From: Mario Kleiner Date: Mon, 21 Feb 2011 04:42:02 +0000 (+0100) Subject: drm/vblank: Enable precise vblank timestamps for interlaced and doublescan modes. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9be6f8a978bdcbab46474a125aa4212516b71fe7;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git drm/vblank: Enable precise vblank timestamps for interlaced and doublescan modes. Testing showed the current code can already handle doublescan video modes just fine. A trivial tweak makes it work for interlaced scanout as well. Tested and shown to be precise on Radeon rv530, r600 and Intel 945-GME. Signed-off-by: Mario Kleiner Signed-off-by: Dave Airlie --- diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 22f3bf5ecbd..53120a72a48 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -493,6 +493,12 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc) /* Dot clock in Hz: */ dotclock = (u64) crtc->hwmode.clock * 1000; + /* Fields of interlaced scanout modes are only halve a frame duration. + * Double the dotclock to get halve the frame-/line-/pixelduration. + */ + if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE) + dotclock *= 2; + /* Valid dotclock? */ if (dotclock > 0) { /* Convert scanline length in pixels and video dot clock to @@ -605,14 +611,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc, return -EAGAIN; } - /* Don't know yet how to handle interlaced or - * double scan modes. Just no-op for now. - */ - if (mode->flags & (DRM_MODE_FLAG_INTERLACE | DRM_MODE_FLAG_DBLSCAN)) { - DRM_DEBUG("crtc %d: Noop due to unsupported mode.\n", crtc); - return -ENOTSUPP; - } - /* Get current scanout position with system timestamp. * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times * if single query takes longer than max_error nanoseconds.