[Intel-gfx] [PATCH v4 03/31] drm/amdgpu: Don't register backlight when another backlight should be used (v3)

Hans de Goede
2022-08-24T12:16:37Z

Before this commit when we want userspace to use the acpi_video backlight
device we register both the GPU's native backlight device and acpi_video's
firmware acpi_video# backlight device. This relies on userspace preferring
firmware type backlight devices over native ones.

Registering 2 backlight devices for a single display really is
undesirable, don't register the GPU's native backlight device when
another backlight device should be used.

Changes in v2:
- To avoid linker errors when amdgpu is builtin and video_detect.c is in
a module, select ACPI_VIDEO and its deps if ACPI is enabled.
When ACPI is disabled, ACPI_VIDEO is also always disabled, ensuring
the stubs from acpi/video.h will be used.

Changes in v3:
- Use drm_info(drm_dev, "...") to log messages
- ACPI_VIDEO can now be enabled on non X86 too,
adjust the Kconfig changes to match this.

Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/gpu/drm/Kconfig | 7 +++++++
drivers/gpu/drm/amd/amdgpu/atombios_encoders.c | 7 +++++++
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 7 +++++++
3 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 0b2ad7212ee6..95ca33938b4a 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -259,6 +259,13 @@ config DRM_AMDGPU
select BACKLIGHT_CLASS_DEVICE
select INTERVAL_TREE
select DRM_BUDDY
+ # amdgpu depends on ACPI_VIDEO when ACPI is enabled, for select to work
+ # ACPI_VIDEO's dependencies must also be selected.
+ select INPUT if ACPI
+ select ACPI_VIDEO if ACPI
+ # On x86 ACPI_VIDEO also needs ACPI_WMI
+ select X86_PLATFORM_DEVICES if ACPI && X86
+ select ACPI_WMI if ACPI && X86
help
Choose this option if you have a recent AMD Radeon graphics card.

diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
index fa7421afb9a6..b4e3cedceaf8 100644
--- a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
+++ b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
@@ -26,6 +26,8 @@

#include <linux/pci.h>

+#include <acpi/video.h>
+
#include <drm/drm_crtc_helper.h>
#include <drm/amdgpu_drm.h>
#include "amdgpu.h"
@@ -184,6 +186,11 @@ void amdgpu_atombios_encoder_init_backlight(struct amdgpu_encoder *amdgpu_encode
if (!(adev->mode_info.firmware_flags & ATOM_BIOS_INFO_BL_CONTROLLED_BY_GPU))
return;

+ if (!acpi_video_backlight_use_native()) {
+ drm_info(dev, "Skipping amdgpu atom DIG backlight registration\n");
+ return;
+ }
+
pdata = kmalloc(sizeof(struct amdgpu_backlight_privdata), GFP_KERNEL);
if (!pdata) {
DRM_ERROR("Memory allocation failed\n");
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 e702f0d72d53..706c67f4bda8 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -90,6 +90,8 @@
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_plane_helper.h>

+#include <acpi/video.h>
+
#include "ivsrcid/dcn/irqsrcs_dcn_1_0.h"

#include "dcn/dcn_1_0_offset.h"
@@ -4033,6 +4035,11 @@ amdgpu_dm_register_backlight_device(struct amdgpu_display_manager *dm)
amdgpu_dm_update_backlight_caps(dm, dm->num_of_edps);
dm->brightness[dm->num_of_edps] = AMDGPU_MAX_BL_LEVEL;

+ if (!acpi_video_backlight_use_native()) {
+ drm_info(adev_to_drm(dm->adev), "Skipping amdgpu DM backlight registration\n");
+ return;
+ }
+
props.max_brightness = AMDGPU_MAX_BL_LEVEL;
props.brightness = AMDGPU_MAX_BL_LEVEL;
props.type = BACKLIGHT_RAW;
--
2.37.2