[PATCH 11/13] drm/amd/display: Add signal type check when verify stream backends same

Wayne Lin Wayne.Lin at amd.com
Fri Jan 14 01:36:55 UTC 2022

From: Dale Zhao <dale.zhao at amd.com>

For allow eDP hot-plug feature, the stream signal may change to VIRTUAL
when plug-out and back to eDP when plug-in. OS will still setPathMode
with same timing for each plugging, but eDP gets no stream update as we
don't check signal type changing back as keeping it VIRTUAL. It's also
unsafe for future cases that stream signal is switched with same timing.

Check stream signal type change include previous HDMI signal case.

Reviewed-by: Aric Cyr <Aric.Cyr at amd.com>
Acked-by: Wayne Lin <wayne.lin at amd.com>
Signed-off-by: Dale Zhao <dale.zhao at amd.com>
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index b3912ff9dc91..b34bf59cf54b 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -1640,6 +1640,9 @@ static bool are_stream_backends_same(
 	if (is_timing_changed(stream_a, stream_b))
 		return false;
+	if (stream_a->signal != stream_b->signal)
+		return false;
 	if (stream_a->dpms_off != stream_b->dpms_off)
 		return false;

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