This is a note to let you know that I've just added the patch titled
drm/i915: Fix intel_dp_mst_best_encoder()
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-fix-intel_dp_mst_best_encoder.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit fd431f2a891d3a7e795b500189c1f5de1d557521
Author: Lyude Paul <lyude@xxxxxxxxxx>
Date: Mon Oct 8 19:24:34 2018 -0400
drm/i915: Fix intel_dp_mst_best_encoder()
[ Upstream commit a9f9ca33d1fe9325f414914be526c0fc4ba5281c ]
Currently, i915 appears to rely on blocking modesets on
no-longer-present MSTB ports by simply returning NULL for
->best_encoder(), which in turn causes any new atomic commits that don't
disable the CRTC to fail. This is wrong however, since we still want to
allow userspace to disable CRTCs on no-longer-present MSTB ports by
changing the DPMS state to off and this still requires that we retrieve
an encoder.
So, fix this by always returning a valid encoder regardless of the state
of the MST port.
Changes since v1:
- Remove mst atomic helper, since this got replaced with a much simpler
solution
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://patchwork.freedesktop.org/patch/msgid/20181008232437.5571-6-lyude@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 1fec0c71b4d95..58ba14966d4f1 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -408,8 +408,6 @@ static struct drm_encoder *intel_mst_atomic_best_encoder(struct drm_connector *c
struct intel_dp *intel_dp = intel_connector->mst_port;
struct intel_crtc *crtc = to_intel_crtc(state->crtc);
- if (!READ_ONCE(connector->registered))
- return NULL;
return &intel_dp->mst_encoders[crtc->pipe]->base.base;
}
