On Mon, 26 Sep 2016 10:57:50 +0200, Michel D4nzer wrote: > > On 23/09/16 10:06 PM, Takashi Iwai wrote: > > radeon_cursor_move_unlock() contains a workaround for AVIVO chips that > > are older than DCE6 when the cursor ends on 128 pixel boundary. It > > decreases the position when the calculated end position is on 128 > > pixel boundary. However, it hits also the condition where x=-1 and > > width=1 are passed, since cursor_end is 0 (which is aligned with 128, > > too). Then the value gets decreased and it hits WARN_ON_ONCE() > > below, eventually screws up the GPU. > > > > The fix is simply to skip the workaround when x is already zero. > > Also, remove the superfluous WARN_ON_ON() for the negative value check > > that wouldn't happen any longer after this change. > > > > Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1000433 > > Cc: <stable@xxxxxxxxxxxxxxx> > > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> > > --- > > drivers/gpu/drm/radeon/radeon_cursor.c | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/radeon/radeon_cursor.c b/drivers/gpu/drm/radeon/radeon_cursor.c > > index 2a10e24b34b1..4e436eb49a56 100644 > > --- a/drivers/gpu/drm/radeon/radeon_cursor.c > > +++ b/drivers/gpu/drm/radeon/radeon_cursor.c > > @@ -193,10 +193,8 @@ static int radeon_cursor_move_locked(struct drm_crtc *crtc, int x, int y) > > if (w <= 0) { > > w = 1; > > cursor_end = x - xorigin + w; > > - if (!(cursor_end & 0x7f)) { > > + if (x > 0 && !(cursor_end & 0x7f)) > > x--; > > - WARN_ON_ONCE(x < 0); > > - } > > } > > The problem with this change is that the horizontal cursor end position > can again and up as a multiple of 128, which this code is trying to > avoid, because it can break the cursor with some versions of AVIVO / DCE > display engines. > > Attached is a proof-of-concept (only compile tested) alternative fix > which hides the cursor while it's out of bounds. I'll test it, clean it > up and split it up into multiple patches when I get a chance, but maybe > you or the reporter of the referenced bug can test it in the meantime. Sure, I'll ask the reporter to test with your tentative fix. Thanks! Takashi _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
