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| author | Adrian Betschart <adrian.betschart@cinemaone.ch> | 2026-09-11 17:13:14 +0200 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-10-01 17:18:05 -0400 |
| commit | 106b4a2a78b2a2f14885604891957b84bba502db (patch) | |
| tree | 5d40eef2428fb1a4791ab46a4b19091a5910eac2 /Documentation/gpu/amdgpu/driver-misc.rst | |
| download | linux-stable-106b4a2a78b2a2f14885604891957b84bba502db.tar.gz linux-stable-106b4a2a78b2a2f14885604891957b84bba502db.zip | |
drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted
amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and
uses the first encoding that validates. YCbCr 4:4:4 is listed before
RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the
"color format" property is left at AUTO, even though RGB fits the same
link.
That contradicts the documented AUTO behaviour for HDMI in enum
drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when
the bandwidth is not available or the mode is 4:2:0-only), which the
amdgpu implementation of the property also describes. It also leaves
the "Broadcast RGB" property without effect on such sinks, since the
quantization range it selects only applies to RGB output.
Try RGB first. The mask still holds every encoding the sink supports,
so a mode that cannot carry RGB falls back exactly as before.
For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced
through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI
sink that advertised it.
Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation")
Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Assisted-by: Claude Code:claude-fable-5-1
Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch>
Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)
Diffstat (limited to 'Documentation/gpu/amdgpu/driver-misc.rst')
| -rw-r--r-- | Documentation/gpu/amdgpu/driver-misc.rst | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/Documentation/gpu/amdgpu/driver-misc.rst b/Documentation/gpu/amdgpu/driver-misc.rst new file mode 100644 index 000000000..e1a964c3a --- /dev/null +++ b/Documentation/gpu/amdgpu/driver-misc.rst @@ -0,0 +1,156 @@ +================================ + Misc AMDGPU driver information +================================ + +GPU Product Information +======================= + +Information about the GPU can be obtained on certain cards +via sysfs + +product_name +------------ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: product_name + +product_number +-------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: product_number + +serial_number +------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: serial_number + +fru_id +------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: fru_id + +manufacturer +------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: manufacturer + +unique_id +--------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: unique_id + +board_info +---------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: board_info + +GPU Memory Usage Information +============================ + +Various memory accounting can be accessed via sysfs + +mem_info_vram_total +------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c + :doc: mem_info_vram_total + +mem_info_vram_used +------------------ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c + :doc: mem_info_vram_used + +mem_info_vis_vram_total +----------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c + :doc: mem_info_vis_vram_total + +mem_info_vis_vram_used +---------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c + :doc: mem_info_vis_vram_used + +mem_info_gtt_total +------------------ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c + :doc: mem_info_gtt_total + +mem_info_gtt_used +----------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c + :doc: mem_info_gtt_used + +PCIe Accounting Information +=========================== + +pcie_bw +------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pcie_bw + +pcie_replay_count +----------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: pcie_replay_count + +GPU SmartShift Information +========================== + +GPU SmartShift information via sysfs + +smartshift_apu_power +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: smartshift_apu_power + +smartshift_dgpu_power +--------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: smartshift_dgpu_power + +smartshift_bias +--------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: smartshift_bias + +UMA Carveout +============ + +Some versions of Atom ROM expose available options for the VRAM carveout sizes, +and allow changes to the carveout size via the ATCS function code 0xA on supported +BIOS implementations. + +For those platforms, users can use the following files under uma/ to set the +carveout size, in a way similar to what Windows users can do in the "Tuning" +tab in AMD Adrenalin. + +Note that for BIOS implementations that don't support this, these files will not +be created at all. + +uma/carveout_options +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: uma/carveout_options + +uma/carveout +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: uma/carveout |
