Op 13-11-15 om 14:28 schreef Ander Conselvan De Oliveira: > On Thu, 2015-11-12 at 14:58 +0100, Maarten Lankhorst wrote: >> Op 12-11-15 om 14:37 schreef Ander Conselvan De Oliveira: >>> On Wed, 2015-11-11 at 15:36 +0100, Maarten Lankhorst wrote: >>>> When disable_noatomic is called plane_mask is not reliable yet, >>>> and plane_state->visible = true even after disabling the primary plane. >>> So the stale value of plane_state->visible causes a subsequent modeset to >>> enable >>> the primary again? >> Probably not because it would get recalculated in calc_changes, but it should >> really be set to false afterwards. > So basically I didn't understand how the wrong value of plane_state->visible > causes the bug that was mentioned. I think a brief explanation in the commit > message would be good. Well, apply with git am --scissors. Same patch but mentioning this. Is this better? ---->8----- When disable_noatomic is called plane_mask is not correct yet, and plane_state->visible = true is left as true after disabling the primary plane. Other planes are already disabled as part of crtc sanitization, only the primary is left active. But the plane_mask is not updated here. It gets updated during fb takeover in modeset_gem_init, or set to the new value on resume. This means that to disable the primary plane 1 << drm_plane_index(primary) needs to be used. Afterwards because the crtc is no longer active it's forbidden to keep plane_state->visible set, or a WARN_ON in intel_plane_atomic_calc_changes triggers. There are other code points that rely on accurate plane_state->visible too, so make sure the bool is cleared. The other planes are already disabled in intel_sanitize_crtc, so they don't have to be handled here. Cc: stable@xxxxxxxxxxxxxxx #v4.3, v4.2? Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92655 Tested-by: Tomas Mezzadra <tmezzadra@xxxxxxxxx> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_display.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index b5f7493213b7..bc3282ab5ed2 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6267,9 +6267,11 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc) WARN_ON(intel_crtc->unpin_work); intel_pre_disable_primary(crtc); + + intel_crtc_disable_planes(crtc, 1 << drm_plane_index(crtc->primary)); + to_intel_plane_state(crtc->primary->state)->visible = false; } - intel_crtc_disable_planes(crtc, crtc->state->plane_mask); dev_priv->display.crtc_disable(crtc); intel_crtc->active = false; intel_update_watermarks(crtc); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html