linux.git/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.c, branch master

drm/amd/display: Enable DCN6 sources compilation

2026-08-06T13:53:32+00:00

- Add hooks in various entry points to perform hw/sw init for DCN6 asic
- Add dependent changes needed to enable DCN6 asic
- Update the Makefiles so that DCN6 related newly added sources are compiled

Signed-off-by: Aurabindo Pillai 
Signed-off-by: Roman Li 
Reviewed-by: Ivan Lipski 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Replace amdgpu_dm_kunit_helpers.h with dm_helpers.h

2026-07-28T22:32:36+00:00

Drop the amdgpu_dm_kunit_helpers.h include across the amdgpu_dm source
files and use dm_helpers.h instead

Assisted-by: Copilot:Claude-Opus-4.8
Reviewed-by: Alex Hung 
Signed-off-by: Bhawanpreet Lakha 
Signed-off-by: Wayne Lin 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: add VBIOS bounding box KUnit test

2026-07-28T22:32:05+00:00

[WHAT]
Add a KUnit test for dm_dmub_get_vbios_bounding_box() covering the
default IP-version path that returns NULL without allocating GPU memory
or issuing GPINT commands.

Assisted-by: Copilot:Claude-Opus-4.8 GPT-5.5
Reviewed-by: Bhawanpreet Lakha 
Signed-off-by: Alex Hung 
Signed-off-by: Wayne Lin 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: add DMUB command sync KUnit coverage

2026-07-28T22:31:59+00:00

[WHAT]
Add KUnit coverage for the synchronous DMUB command helpers:
dm_execute_dmub_cmd(), amdgpu_dm_process_dmub_aux_transfer_sync(), and
amdgpu_dm_process_dmub_set_config_sync(). Cover command submission
without a DC DMUB service, AUX engine-acquire failure, protocol-error
propagation, the bounded reply-data copy, the zero-length reply branch,
and the SET_CONFIG completed-with-unknown-error path.

Assisted-by: Copilot:Claude-Opus-4.8 GPT-5.5
Reviewed-by: Bhawanpreet Lakha 
Signed-off-by: Alex Hung 
Signed-off-by: Wayne Lin 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: add fused IO KUnit coverage

2026-07-28T22:31:55+00:00

[WHAT]
Add KUnit coverage for the DMUB fused IO helpers: the
dm_dmub_aux_fused_io_callback() NULL-argument guard and the
abort_fused_io() no-DMUB-service path.

Assisted-by: Copilot:Claude-Opus-4.8 GPT-5.5
Reviewed-by: Bhawanpreet Lakha 
Signed-off-by: Alex Hung 
Signed-off-by: Wayne Lin 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Allocate DCN32/1 dmub memory to GTT

2026-07-15T13:15:39+00:00

[Why]
On DCN32/321  sometimes DMCUB takes a long time to flush.
This adds a delay before the data is available on the driver side even
after driver receives notification from DMCUB via inbox

[How]
Allocating DMUB memory to GTT gives much better latency. Limit this to
DCN32/1 for now; it will be made general to all other dGPUs later.

Reviewed-by: Aurabindo Pillai 
Reviewed-by: Sun peng (Leo) Li 
Signed-off-by: Fangzhi Zuo 
Signed-off-by: George Zhang 
Signed-off-by: Alex Deucher

drm/amd/display: Generalize DMUB memory flushes from host

2026-07-14T23:12:34+00:00

[WHY&HOW]
Add DMUB service context to aid in platform abstraction when
flushing memory from the host.

Reviewed-by: Nicholas Kazlauskas 
Signed-off-by: Dillon Varone 
Signed-off-by: George Zhang 
Signed-off-by: Alex Deucher

drm/amd/display: Fix sign mismatch warning

2026-07-08T18:20:30+00:00

Using mismatched signedness (int and uint32_t) causes a -Wsign-compare
warning. Fix it by changing the min macro to min_t to explicitly cast.

Fixes: 8cbe3648aa86 ("drm/amd/display: clamp DMUB AUX reply length to payload buffer")
Signed-off-by: George Zhang 
Reviewed-by: Aurabindo Pillai 
Signed-off-by: Alex Deucher

drm/amd/display: clamp DMUB AUX reply length to payload buffer

2026-07-01T15:34:29+00:00

[Why]
amdgpu_dm_process_dmub_aux_transfer_sync() copies p_notify->aux_reply.length
bytes into payload->data without clamping. payload->data is typically a 16-byte
DPCD scratch buffer, while aux_reply.length is echoed from the sink via the DMUB
ring. While this is clamped by DMUB it's prudent to ensure we validate
this in the driver as well.

[How]
Clamp the copy to sizeof(aux_reply.data), the scratch buffer the reply was read
into, and use that for both the memcpy and the return value. For regular
transfers additionally clamp to payload->length to cover callers whose
destination buffer is smaller than 16 bytes. The write-status-update retry path
(dce_aux_transfer_with_retries) deliberately zeroes payload->length while still
expecting the partial-write status byte, so that bound is skipped in that case
to avoid dropping the reply. Also guard against a NULL payload->data.

Fixes: 81927e2808be ("drm/amd/display: Support for DMUB AUX")
Assisted-by: Copilot:claude-opus-4.8
Reviewed-by: Alex Hung 
Signed-off-by: Harry Wentland 
Signed-off-by: George Zhang 
Signed-off-by: Alex Deucher

drm/amd/display: Simplify DMUB notify registration

2026-07-01T15:31:36+00:00

[WHAT]
Use an early guard for invalid DMUB notify callback registration inputs.
This keeps the same accepted and rejected cases while removing the
redundant else block.

Assisted-by: Copilot:GPT-5
Reviewed-by: Chen-Yu Chen 
Signed-off-by: Alex Hung 
Signed-off-by: George Zhang 
Signed-off-by: Alex Deucher