linux/drivers/gpu/drm/amd/display/dc, branch master

drm/amd/display: Wrap DCN32 phantom-plane allocation in DC_RUN_WITH_PREEMPTION_ENABLED

2026-05-11T21:53:31Z

[Why] dcn32_validate_bandwidth() wraps dcn32_internal_validate_bw() with DC_FP_START()/DC_FP_END(). In x86 non-RT, DC_FP_START takes fpregs_lock(), which disables local softirqs. The DML1 path through dcn32_enable_phantom_plane() calls kvzalloc() to allocate ~335 KiB for dc_plane_state. This triggers the vmalloc path, which calls BUG_ON(in_interrupt()) because it's invoked within the FPU-enabled (softirq disabled) region, leading to a kernel crash. [How] Wrap the dc_state_create_phantom_plane() call with the DC_RUN_WITH_PREEMPTION_ENABLED() macro to allow preemption during this memory allocation. Fixes: 235c67634230 ("drm/amd/display: add DCN32/321 specific files for Display Core") Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/4470 Reviewed-by: Aurabindo Pillai Signed-off-by: Mikhail Gavrilov Signed-off-by: James Lin Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 885ccbef7b94a8b38f69c4211c679021aa27ad11) Cc: stable@vger.kernel.org

drm/amd/display: Read EDID from VBIOS embedded panel info

2026-04-29T14:41:40Z

Some board manufacturers hardcode the EDID for the embedded panel in the VBIOS. This EDID should be used when the panel doesn't have a DDC. For reference, see the legacy non-DC display code: amdgpu_atombios_encoder_get_lcd_info() This is necessary to support embedded connectors without DDC. Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)") Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192 Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit eb105e63b474c11ef6a84a1c6b18100d851ff364)

drm/amd/display: Allow constructing DCE8 link encoder without DDC

2026-04-29T14:41:34Z

When the DDC channel ID is set to CHANNEL_ID_UNKNOWN, pass NULL to the AUX regs array. This is necessary to support embedded connectors without DDC. Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)") Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192 Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit 155baf3038c1af50b602723022ed869b38e86a99)

drm/amd/display: Allow constructing DCE6 link encoder without DDC

2026-04-29T14:41:28Z

When the DDC channel ID is set to CHANNEL_ID_UNKNOWN, pass NULL to the AUX regs array. This is necessary to support embedded connectors without DDC. Fixes: 7c15fd86aaec ("drm/amd/display: dc/dce: add initial DCE6 support (v10)") Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192 Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit 38a70e50b22a188ff601740d64dd75f46213121f)

drm/amd/display: Allow DCE link encoder without AUX registers

2026-04-29T14:41:22Z

Allow constructing the DCE link encoder without DDC, which means the AUX registers array will be NULL. This is necessary to support embedded connectors without DDC. Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)") Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192 Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit 87f30b101af62590faf6020d106da07efdda199b)

drm/amd/display: Allow embedded connectors without DDC

2026-04-29T14:41:15Z

On some laptops, the embedded panel may not have a DDC (display data channel) available. On these, the EDID may be hardcoded in ACPI or the VBIOS. In this case, use GPIO_DDC_LINE_UNKNOWN and don't fail. Fixes: def3488eb0fd ("drm/amd/display: refactor HPD to increase flexibility") Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192 Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit 75b8a6ca0e8bc3ce24572f854e95f8721b321179)

drm/amd/display: Update MCIF_ADDR macro to address IGT DWB regression

2026-04-28T19:45:28Z

[Why] A previous warning-fix commit updated type casts in the DCN3 mmhubbub code but missed updating the MCIF_ADDR macro to the correct, fully parenthesized and casted version. This caused a regression during DWB tests, where address values could be misinterpreted, potentially leading to incorrect hardware programming. [How] Updated the MCIF_ADDR macro in dcn30_mmhubbub.c to use the proper parenthesization and type casting, ensuring correct address handling. Removed redundant casts from REG_UPDATE calls for improved clarity and consistency with current coding standards. Fixes: f4cdbb5d5405 ("drm/amd/display: Fix implicit narrowing conversion warnings") Reviewed-by: Clayton King Signed-off-by: Gaghik Khachatrian Signed-off-by: Tom Chung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 4f251a5e9f2297023b00b7cab606de111931cfa3)

drm/amd/display: Restore analog connector support

2026-04-24T15:08:15Z

[Why] The analog connector support was accidentally removed, causing a crash when connecting an analog monitor. [How] This patch restores the functions and pointers required for proper analog and DP bridge encoder support on legacy GPUs. V2: Restore the external encoder control functions. V3: - Restore BIOS parser external encoder DAC load detection - Restore stream initialization and source selection changes Fixes: e56e3cff2a1b ("drm/amd/display: Sync dcn42 with DC 3.2.373") Cc: Timur Kristóf Signed-off-by: Roman Li Reviewed-by: Alex Hung Reviewed-by: Timur Kristóf Tested-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit cea8349e4494d2892ea57eef3fe4a8987464a876)

drm/amd/display: Disable 10-bit truncation and dithering on DCE 6.x

2026-04-21T21:03:33Z

DCE 6.x doesn't support 10-bit truncation and 10-bit dithering because the following fields are 1-bit only: FMT_TEMPORAL_DITHER_DEPTH FMT_SPATIAL_DITHER_DEPTH FMT_TRUNCATE_DEPTH Programming these fields to "2" will program them as if the dithering option was 6-bit, resulting in sub-par picture quality and an ugly "color banding" effect. Note that a recent commit changed the default 10-bit dithering option to DITHER_OPTION_SPATIAL10 which improves the picture quality because it happens to look better, but is still not actually supported by DCE 6.x versions. When the color depth is 10-bit or more, just disable any kind of dithering options on DCE 6.x. Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5151 Fixes: 529cad0f945c ("drm/amd/display: Add function to set dither option") Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit 6be8ced880dfe29ce38c2d5e74489822da5c250e)

drm/amd/display: Move dml2_destroy to non-FPU compilation unit

2026-04-17T19:25:27Z

On PREEMPT_RT kernels, vfree() can sleep because spin_lock is converted to rt_mutex. dml2_destroy() calls vfree() while inside an FPU-guarded region (preempt_count=2), which is illegal. dml2_wrapper_fpu.c is compiled with CC_FLAGS_FPU which defines _LINUX_FPU_COMPILATION_UNIT, making DC_RUN_WITH_PREEMPTION_ENABLED() resolve to a no-op. This prevents the macro from cycling FPU context off/on around vfree(). Move dml2_destroy() to dml2_wrapper.c (non-FPU compilation unit) where DC_RUN_WITH_PREEMPTION_ENABLED() properly cycles DC_FP_END/ DC_FP_START around vfree(). This pairs it with dml2_allocate_memory() which already lives there. Reviewed-by: Dillon Varone Signed-off-by: Rafal Ostrowski Signed-off-by: Chenyu Chen Signed-off-by: Alex Deucher