kernel/linux.git/drivers/gpu/drm/amd/display/dc/hwss, branch linux-7.0.y

drm/amd/display: Fix NULL pointer dereference in dcn401_init_hw()

2026-03-30T20:18:47+00:00

dcn401_init_hw() assumes that update_bw_bounding_box() is valid when entering the update path. However, the existing condition: ((!fams2_enable && update_bw_bounding_box) || freq_changed) does not guarantee this, as the freq_changed branch can evaluate to true independently of the callback pointer. This can result in calling update_bw_bounding_box() when it is NULL. Fix this by separating the update condition from the pointer checks and ensuring the callback, dc->clk_mgr, and bw_params are validated before use. Fixes the below: ../dc/hwss/dcn401/dcn401_hwseq.c:367 dcn401_init_hw() error: we previously assumed 'dc->res_pool->funcs->update_bw_bounding_box' could be null (see line 362) Fixes: ca0fb243c3bb ("drm/amd/display: Underflow Seen on DCN401 eGPU") Cc: Daniel Sa Cc: Alvin Lee Cc: Roman Li Cc: Alex Hung Cc: Tom Chung Cc: Dan Carpenter Cc: Aurabindo Pillai Signed-off-by: Srinivasan Shanmugam Reviewed-by: Alex Hung Signed-off-by: Alex Deucher (cherry picked from commit 86117c5ab42f21562fedb0a64bffea3ee5fcd477) Cc: stable@vger.kernel.org

drm/amd/display: Fallback to boot snapshot for dispclk

2026-03-02T22:13:52+00:00

[WHY & HOW] If the dentist is unavailable, fallback to reading CLKIP via the boot snapshot to get the current dispclk. Reviewed-by: Nicholas Kazlauskas Signed-off-by: Dillon Varone Signed-off-by: Alex Hung Cc: Mario Limonciello Cc: Alex Deucher Tested-by: Dan Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 2ab77600d1e55a042c02437326d3c7563e853c6c) Cc: stable@vger.kernel.org

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

drm/amd/display: Enable DAC in DCE link encoder

2026-02-19T17:16:12+00:00

Ensure that the DAC output is enabled at the correct time by moving it to the DCE link encoder similarly to how digital outputs are enabled. This also removes the call to DAC1EncoderControl from the DCE HWSS, which always felt like it was a hacky solution. Fixes: 0fbe321a93ce ("drm/amd/display: Implement DCE analog link encoders (v2)") Signed-off-by: Timur Kristóf Tested-by: Mauro Rossi Reviewed-by: Alex Hung Signed-off-by: Alex Deucher

drm/amd/display: Set CRTC source for DAC using registers

2026-02-19T17:16:12+00:00

Apparently the VBIOS SelectCRTC_Source function overwrites a few registers (such as FMT_*) which DC writes in a different place, which can cause problems. Instead of using the SelectCRTC_Source function from the VBIOS, use the DAC_SOURCE_SELECT register directly, similarly to how it is done for digital link encoders. Fixes: 3be26d81b150 ("drm/amd/display: Support DAC in dce110_hwseq") Signed-off-by: Timur Kristóf Tested-by: Mauro Rossi Reviewed-by: Alex Hung Signed-off-by: Alex Deucher

drm/amd/display: Turn off DAC in DCE link encoder using VBIOS

2026-02-19T17:16:12+00:00

Apparently, the VBIOS DAC1EncoderControl function is much more graceful about turning off the DAC. It writes various DAC registers in a specific sequence. Use that instead of just clearing the DAC_ENABLE register. Do this in just the dce110_link_encoder_disable_output function and remove it from the HWSS. Fixes: 0fbe321a93ce ("drm/amd/display: Implement DCE analog link encoders (v2)") Signed-off-by: Timur Kristóf Tested-by: Mauro Rossi Suggested-by: Alex Deucher Reviewed-by: Alex Hung Signed-off-by: Alex Deucher

drm/amd/display: Check return of shaper curve to HW format

2026-02-19T17:16:11+00:00

[Why & How] Check return of cm3_helper_translate_curve_to_hw_format. This is reported as a CHECKED_RETURN error by Coverity. Reviewed-by: Aurabindo Pillai Signed-off-by: Alex Hung Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Correct logic check error for fastboot

2026-02-19T17:16:11+00:00

[Why] Fix fastboot broken in driver. This is caused by an open source backport change 7495962c. from the comment, the intended check is to disable fastboot for pre-DCN10. but the logic check is reversed, and causes fastboot to be disabled on all DCN10 and after. fastboot is for driver trying to pick up bios used hw setting and bypass reprogramming the hw if dc_validate_boot_timing() condition meets. Fixes: 7495962cbceb ("drm/amd/display: Disable fastboot on DCE 6 too") Cc: stable@vger.kernel.org Reviewed-by: Mario Limonciello Reviewed-by: Ovidiu Bunea Signed-off-by: Charlene Liu Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Migrate DCCG registers access from hwseq to dccg component.

2026-02-19T17:16:10+00:00

[Why] Direct DCCG register access in hwseq layer was creating register conflicts. [How] Migrated DCCG registers from hwseq-dccg component. Reviewed-by: Martin Leung Signed-off-by: Bhuvanachandra Pinninti Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher