Commit "c0fe07a drm/qxl: rewrite framebuffer support" has a bug in the dirty rectangle tracking: Instead of ignoring an empty dirty rectangle when adding a new dirty region the dirty region gets extended to the upper left corner. Fix it.

Cc: linux-stable@vger.kernel.org Signed-off-by: Gerd Hoffmann kraxel@redhat.com --- drivers/gpu/drm/qxl/qxl_fb.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/qxl/qxl_fb.c b/drivers/gpu/drm/qxl/qxl_fb.c index 2bbe6b8..f2f6d11 100644 --- a/drivers/gpu/drm/qxl/qxl_fb.c +++ b/drivers/gpu/drm/qxl/qxl_fb.c @@ -144,14 +144,17 @@ static void qxl_dirty_update(struct qxl_fbdev *qfbdev,

spin_lock_irqsave(&qfbdev->dirty.lock, flags);

- if (qfbdev->dirty.y1 < y) - y = qfbdev->dirty.y1; - if (qfbdev->dirty.y2 > y2) - y2 = qfbdev->dirty.y2; - if (qfbdev->dirty.x1 < x) - x = qfbdev->dirty.x1; - if (qfbdev->dirty.x2 > x2) - x2 = qfbdev->dirty.x2; + if ((qfbdev->dirty.y2 - qfbdev->dirty.y1) && + (qfbdev->dirty.x2 - qfbdev->dirty.x1)) { + if (qfbdev->dirty.y1 < y) + y = qfbdev->dirty.y1; + if (qfbdev->dirty.y2 > y2) + y2 = qfbdev->dirty.y2; + if (qfbdev->dirty.x1 < x) + x = qfbdev->dirty.x1; + if (qfbdev->dirty.x2 > x2) + x2 = qfbdev->dirty.x2; + }

qfbdev->dirty.x1 = x; qfbdev->dirty.x2 = x2;