[PATCH v2 12/12] drm/amd/display: Skip panel power savings on eDP links without a panel

[Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>]

From: Andre Eikmeyer <dev@deq.rocks>

When GMUX routes the internal panel to the integrated GPU, the eDP link
of the AMD GPU has no sink. It still exposed panel_power_savings, and
tuned writes it on every switch between AC and battery. Each write sends
a hotplug event and the following connector probe runtime resumes the
GPU that GMUX had powered off. Only create the attribute when the link
has a panel.

Tested-by: Sebastian Zygadlo <szgit@icloud.com>
Tested-by: Yossef Osman <yossef.osman@proton.me>
Signed-off-by: Andre Eikmeyer <dev@deq.rocks>
Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c    | 3 +++
 .../drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c | 1 +
 2 files changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
index 703d0617d..c8fbd2167 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
@@ -761,6 +761,9 @@ amdgpu_dm_should_create_sysfs(struct amdgpu_dm_connector *amdgpu_dm_connector)
 	if (amdgpu_dm_connector->base.connector_type != DRM_MODE_CONNECTOR_eDP)
 		return false;
 
+	if (!amdgpu_dm_connector->dc_link->edp_sink_present)
+		return false;
+
 	if (link->panel_type != PANEL_TYPE_LCD && !link->panel_config.cacp.cacp_supported)
 		return false;
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
index 7ca17f803..d71f5e5da 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
@@ -52,6 +52,7 @@ static void setup_test_connector(struct kunit *test,
 	fixture->aconnector->dc_link = fixture->link;
 	fixture->aconnector->base.dev = &fixture->adev->ddev;
 	fixture->link->connector_signal = signal;
+	fixture->link->edp_sink_present = true;
 }
 
 static void setup_test_dm_ddev(struct kunit *test, struct amdgpu_display_manager *dm)
-- 
2.55.0