On Thursday, 19 September 2019 14:30:02 BST Mihail Atanassov wrote:
When initially turning a crtc on, drm_reset_vblank_timestamp will set the vblank timestamp to 0 for any driver that doesn't provide a ->get_vblank_timestamp() hook.
Unfortunately, the FLIP_COMPLETE event depends on that timestamp, and the only way to regenerate a valid one is to have vblank interrupts enabled and have a valid in-ISR call to drm_crtc_handle_vblank.
Wrap the call to komeda_crtc_do_flush in ->atomic_enable() with a drm_crtc_vblank_{get,put} pair so we can have a vblank ISR prior to the FLIP_COMPLETE ISR (or more likely, they'll get handled in the same ISR, which is equally valid).
Cc: Daniel Vetter daniel@ffwll.ch Cc: Liviu Dudau Liviu.Dudau@arm.com Signed-off-by: Mihail Atanassov mihail.atanassov@arm.com
drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c index f4400788ab94..87420a767bc4 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c @@ -258,7 +258,9 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc, { komeda_crtc_prepare(to_kcrtc(crtc)); drm_crtc_vblank_on(crtc);
- WARN_ON(drm_crtc_vblank_get(crtc)); komeda_crtc_do_flush(crtc, old);
- drm_crtc_vblank_put(crtc);
}
static void
Please ignore, this doesn't work (page flips after 5 seconds don't get an updated timestamp because of the delayed vsync disable). I'll push a v2 soon where vsync on/off tracks crtc enable/disable.