atomic_flush will be called for each CRTC even if they aren't enabled. The whole code we have there will thus run without a properly affected channel, which can then result in all sorts of weird behaviour. Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> --- drivers/gpu/drm/vc4/vc4_hvs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c index 2d540fc11357..5db125dc2358 100644 --- a/drivers/gpu/drm/vc4/vc4_hvs.c +++ b/drivers/gpu/drm/vc4/vc4_hvs.c @@ -472,6 +472,9 @@ void vc4_hvs_atomic_flush(struct drm_crtc *crtc, u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start; u32 __iomem *dlist_next = dlist_start; + if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED) + return; + if (debug_dump_regs) { DRM_INFO("CRTC %d HVS before:\n", drm_crtc_index(crtc)); vc4_hvs_dump_state(dev); -- 2.35.1