From 92eb3ea6ab347395ad03ed73da3d75503c3cb966 Mon Sep 17 00:00:00 2001 From: Hoegeun Kwon Date: Thu, 7 Sep 2017 16:24:56 +0900 Subject: [PATCH] drm/vc4: Workaround for crtc scanout device problem Currently, the crtc device does not start a scanout, the time of vblank is always calculated as future value. As a workaround, always change vpos to a positive number. Change-Id: I9d9efa473f530b519637a7497c6a41f5e3c9b541 Signed-off-by: Hoegeun Kwon --- drivers/gpu/drm/vc4/vc4_crtc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index 9449ae6..0ea2ecd 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -176,7 +176,13 @@ static bool vc4_crtc_get_scanout_position(struct drm_crtc *crtc, * contention on event_lock or vblank_time lock in * the core. */ - *vpos = -vblank_lines; + /* + * The scanout does not occur due to device problem. + * Fixed vpos to a positive value with workaround. + * TODO. This issue should be corrected. + * We should check the scanout action of the crtc device. + */ + *vpos = vblank_lines; if (stime) *stime = vc4_crtc->t_vblank; -- 2.7.4