From 81ffbbedc37c6043e5f5b123da926aa7dd8ad60a Mon Sep 17 00:00:00 2001 From: Felix Kuehling Date: Thu, 23 Feb 2012 19:16:12 -0500 Subject: [PATCH] drm/radeon: fix deferred page-flip detection logic on Avivo-based ASICs This fixes page-flip-related flickering observed on Iconia Tab W500. The update_pending status returned by radeon_page_flip is very accurate on Avivo-based ASICs when vpos is negative. Experiments were conducted on several ASIC generations ranging from RS690 to Cayman where the page flip was artificially timed to occur at a specific vpos. With negative vpos, overriding update_pending always lead to flickering. The same experiment on RV380 and RV410 showed that update_pending is not accurate with negative vpos. In most cases update_pending == 1 is returned although the flip would complete before the start of the next frame. Therefore I left the behaviour unchanged for pre-AVIVO ASICs for performance reasons, although this may result in flickering in rare cases. This change also makes the logic a little easier to understand. Signed-off-by: Felix Kuehling Reviewed-by: Mario Kleiner Signed-off-by: Dave Airlie --- drivers/gpu/drm/radeon/radeon_display.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c index 7cb062d..1f98e5f 100644 --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -303,8 +303,17 @@ void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id) if (update_pending && (DRM_SCANOUTPOS_VALID & radeon_get_crtc_scanoutpos(rdev->ddev, crtc_id, &vpos, &hpos)) && - (vpos >=0) && - (vpos < (99 * rdev->mode_info.crtcs[crtc_id]->base.hwmode.crtc_vdisplay)/100)) { + ((vpos >= (99 * rdev->mode_info.crtcs[crtc_id]->base.hwmode.crtc_vdisplay)/100) || + (vpos < 0 && !ASIC_IS_AVIVO(rdev)))) { + /* crtc didn't flip in this target vblank interval, + * but flip is pending in crtc. Based on the current + * scanout position we know that the current frame is + * (nearly) complete and the flip will (likely) + * complete before the start of the next frame. + */ + update_pending = 0; + } + if (update_pending) { /* crtc didn't flip in this target vblank interval, * but flip is pending in crtc. It will complete it * in next vblank interval, so complete the flip at -- 2.7.4