drm/amd/display: Report to ACPI video if no panels were found

[ Upstream commit c573e240609ff781a0246c0c8c8351abd0475287 ]

On desktop APUs amdgpu doesn't create a native backlight device
as no eDP panels are found.  However if the BIOS has reported
backlight control methods in the ACPI tables then an acpi_video0
backlight device will be made 8 seconds after boot.

This has manifested in a power slider on a number of desktop APUs
ranging from Ryzen 5000 through Ryzen 7000 on various motherboard
manufacturers. To avoid this, report to the acpi video detection
that the system does not have any panel connected in the native
driver.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1783786
Reported-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index c2c26fbea51293862825f09c30ae41d888af0958..6f1cc5ce4c7a981e0878b0f409f868c96b54b737 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4372,6 +4372,10 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
                amdgpu_set_panel_orientation(&aconnector->base);
        }
 
+       /* If we didn't find a panel, notify the acpi video detection */
+       if (dm->adev->flags & AMD_IS_APU && dm->num_of_edps == 0)
+               acpi_video_report_nolcd();
+
        /* Software is initialized. Now we can register interrupt handlers. */
        switch (adev->asic_type) {
 #if defined(CONFIG_DRM_AMD_DC_SI)