linux.git/drivers/gpu/drm/amd/display/modules, branch v7.2-rc2

drm/amd/display: guard against overflow in HDCP message dump

2026-07-01T17:00:40+00:00

[Why]
mod_hdcp_dump_binary_message() computed target_size (a uint32_t) as roughly
byte_size * msg_size and gated the whole write on buf_size >= target_size. A
large msg_size can overflow target_size, wrapping it to a small value that
passes the check while the loop still writes byte_size * msg_size bytes
into buf. All current callers pass small constants so this is not reachable
today, but the unchecked arithmetic should be hardened.

[How]
Drop the overflow-prone target_size precomputation and instead bounds-check the
output position on every iteration, stopping once the next entry would not leave
room for the trailing terminator. This cannot overflow and, for oversized
messages, dumps as much as fits rather than printing nothing.

Fixes: 4c283fdac08a ("drm/amd/display: Add HDCP module")
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 
(cherry picked from commit d0a775e5d70b376696245a14c09e3aa6dde0023a)
Cc: stable@vger.kernel.org

drm/amd/display: Add missing kdoc for ALLM parameters

2026-06-03T17:45:53+00:00

Add descriptions for the missing parameters for ALLMEnabled and
ALLMValue  to keep the function documentation synchronized with the
function prototype mod_build_hf_vsif_infopacket().

Fixes the below with gcc W=1:
../display/modules/info_packet/info_packet.c:507 function parameter 'ALLMEnabled' not described in 'mod_build_hf_vsif_infopacket'
../display/modules/info_packet/info_packet.c:507 function parameter 'ALLMValue' not described in 'mod_build_hf_vsif_infopacket'

Fixes: 3c2381b92cba ("drm/amd/display: add support for VSIP info packet")
Cc: Roman Li 
Cc: Alex Hung 
Cc: Tom Chung 
Cc: Aurabindo Pillai 
Cc: Wayne Lin 
Cc: Nicholas Kazlauskas 
Cc: Bhawanpreet Lakha 
Signed-off-by: Srinivasan Shanmugam 
Reviewed-by: Alex Hung 
Signed-off-by: Alex Deucher

drm/amd/display: Update HDCP and info_packet modules for FRL

2026-06-03T17:44:49+00:00

The HDCP module has a minor update for FRL, and info_packet is
updated for ALLM.

Signed-off-by: Harry Wentland 
Reviewed-by: Fangzhi Zuo 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Handle aux_inst for connectors without DDC pin

2026-06-03T17:43:42+00:00

[Why & How]
Must use an alternative codepath to access AUX channel when
link->no_ddc_pin is set.

Reviewed-by: Harry Wentland 
Signed-off-by: Gabe Teeger 
Signed-off-by: Matthew Stewart 
Signed-off-by: Ray Wu 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Clamp HDMI HDCP2 rx_id_list read to buffer size

2026-06-03T17:38:01+00:00

[Why & How]
During HDCP 2.x repeater authentication over HDMI, the driver reads the
sink's RxStatus register and extracts a 10-bit message size field (max
value 1023). This value is used as the read length for the ReceiverID
list without being clamped to the size of the destination buffer
rx_id_list[177]. A malicious HDMI repeater could advertise a message
size larger than the buffer, causing an out-of-bounds write during the
I2C read.

Clamp the read length in mod_hdcp_read_rx_id_list() to the size of the
rx_id_list buffer, matching the approach already used in the DP branch.

Fixes: eff682f83c9c ("drm/amd/display: Add DDC handles for HDCP2.2")
Assisted-by: Copilot:claude-opus-4.6
Reviewed-by: Alex Hung 
Signed-off-by: Harry Wentland 
Signed-off-by: Ray Wu 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Refactor Replay functionality into dedicated power_replay module

2026-05-19T15:45:41+00:00

[Why]
Extract all Replay related functions from power.c and
power_helpers.c into a new power_replay.c module for
better code organization and maintainability.

[How]
Create new power_replay.c file containing
Replay-related functions moved from power.c
and power_helpers.c . Update mod_power.h with
function declarations. Maintain forward
declaration for type compatibility.

Reviewed-by: Robin Chen 
Signed-off-by: Lohita Mudimela 
Signed-off-by: Ivan Lipski 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Refactor PSR functionality into dedicated power_psr module

2026-05-19T15:45:40+00:00

[Why]
Extract all PSR (Panel Self Refresh) related functions from power.c
into a new power_psr.c module for better code organization and
maintainability.

[How]
Create new power_psr.c file containing all PSR-related functions
moved from power.c. Remove static qualifier from shared functions
to enable cross-file access:
- psr_context_to_mod_power_psr_context: Convert PSR context to
  module power PSR context
- map_index_from_stream: Map stream to power entity index
- delay_two_frames: Wait for two frame periods

Add function declarations to header. Maintain forward declaration of struct
core_power for type compatibility.

Reviewed-by: Anthony Koo 
Signed-off-by: Lohita Mudimela 
Signed-off-by: Ivan Lipski 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Fix enum decl warnings

2026-05-11T20:11:03+00:00

[Why]
warnings were triggered by enum forward declarations that are not
valid in C++ without an explicit underlying type.

[How]
- Replace problematic enum forward declarations with C++-safe forms where
  applicable.
- Use plain integer types for interface-only declarations that do not
  require strong enum typing.
- Update dependent winterface signatures and related type usage
  consistently.
- Add required include and type-visibility fixes to avoid follow-on parse
  and type-resolution issues.

Reviewed-by: Aric Cyr 
Signed-off-by: Gaghik Khachatrian 
Signed-off-by: James Lin 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Separate ABM functions into dedicated power_abm.c file

2026-05-11T20:10:51+00:00

[Why]
Improves code organization by separating Adaptive Backlight
Modulation functionality from general power management.
This modular approach enhances maintainability and makes the
codebase easier to navigate.

[How]
Create new power_abm.c file containing all ABM-related functions moved from power.c.
Remove static qualifier from shared functions to enable cross-file access:
- initialize_backlight_caps: Initialize backlight capabilities
- validate_ext_backlight_caps: Validate external backlight capabilities
- backlight_millipercent_to_pwm: Convert brightness percent to PWM
- backlight_millipercent_to_millinit: Convert brightness percent to nits
- fill_backlight_level_params: Populate backlight level parametersAdd function
declarations to mod_power.h header. Update CMakeLists.txt to include power_abm.c in build.
Maintain forward declaration of struct core_power for type compatibility.
Rename struct core_power field from 'public' to 'mod_public'.
Move internal structures (backlight_state, backlight_properties,
dmcu_varibright_cached_properties, core_power) to power_helpers.h to
ensure consistent memory layouts across compilation units.

Reviewed-by: Martin Leung 
Signed-off-by: Lohita Mudimela 
Signed-off-by: James Lin 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Fix warnings

2026-05-11T20:10:34+00:00

[Why & How]
Fix various warnings related to unsigned/signed mismatches
-  Consistently use the same signedness for a given value
-  Explcitly cast between types when needed

Reviewed-by: Dillon Varone 
Signed-off-by: Clay King 
Signed-off-by: James Lin 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher