linux/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c, branch v6.17

drm/amd/display: Add sanity checks for drm_edid_raw()

2025-06-24T14:39:24Z

When EDID is retrieved via drm_edid_raw(), it doesn't guarantee to return proper EDID bytes the caller wants: it may be either NULL (that leads to an Oops) or with too long bytes over the fixed size raw_edid array (that may lead to memory corruption). The latter was reported actually when connected with a bad adapter. Add sanity checks for drm_edid_raw() to address the above corner cases, and return EDID_BAD_INPUT accordingly. Fixes: 48edb2a4256e ("drm/amd/display: switch amdgpu_dm_connector to use struct drm_edid") Link: https://bugzilla.suse.com/show_bug.cgi?id=1236415 Signed-off-by: Takashi Iwai Signed-off-by: Alex Deucher (cherry picked from commit 648d3f4d209725d51900d6a3ed46b7b600140cdf) Cc: stable@vger.kernel.org

drm/amd/display: Fix ACPI edid parsing on some Lenovo systems

2025-04-22T12:51:44Z

[Why] The ACPI EDID in the BIOS of a Lenovo laptop includes 3 blocks, but dm_helpers_probe_acpi_edid() has a start that is 'char'. The 3rd block index starts after 255, so it can't be indexed properly. This leads to problems with the display when the EDID is parsed. [How] Change the variable type to 'short' so that larger values can be indexed. Cc: Renjith Pananchikkal Reported-by: Mark Pearson Suggested-by: David Ober Fixes: c6a837088bed ("drm/amd/display: Fetch the EDID from _DDC if available for eDP") Reviewed-by: Alex Hung Signed-off-by: Mario Limonciello Signed-off-by: Zaeem Mohamed Tested-by: Mark Broadworth Signed-off-by: Alex Deucher

drm/amd/display: HDCP Locality check using DMUB Fused IO

2025-04-07T22:01:07Z

[Why] HDCP locality check has strict timing requirements, currently broken due to reliance on msleep which does not guarantee accuracy. The PR moves the write-poll-read sequence into DMUB using new generic Fused IO interface, where the timing accuracy is greatly improved. New flow is enabled using DCN resource capability bit (none for now), or using a debug flag. [How] * Extended mod_hdcp_config with new function for requesting DMUB to execute a sequence of fused I2C/AUX commands and synchronously wait until an outbox reply arrives or a timeout expires. * If the timeout expires, send an abort to DMUB. * Update HDCP to use the DMUB for locality check if supported. * Add DC_HDCP_LC_FORCE_FW_ENABLE and DC_HDCP_LC_ENABLE_SW_FALLBACK. * Make the first enable new flow regardless of resource capabilities. * Make the second enable fallback to old SW flow. * Clean up makefile source file listings for easier updates. Reviewed-by: Alvin Lee Signed-off-by: Dominik Kaszewski Signed-off-by: Roman Li Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: use drm_* instead of DRM_ in apply_edid_quirks()

2025-03-05T15:46:51Z

drm_* macros are more helpful that DRM_* macros since the former indicates the associated DRM device that prints the error, which maybe helpful when debugging. Signed-off-by: Aurabindo Pillai Reviewed-by: Alex Hung Signed-off-by: Alex Deucher

drm/amd/display: Add workaround for a panel

2025-03-05T15:46:44Z

Implement w/a for a panel which requires 10s delay after link detect. Signed-off-by: Aurabindo Pillai Reviewed-by: Alex Hung Signed-off-by: Alex Deucher

drm/amd/display: Add HBlank reduction DPCD write to DPMS sequence

2025-01-06T19:44:27Z

[Why] Certain small HBlank timings may not have a large enough HBlank to support audio when low bpp DSC is enabled. HBlank expansion by the source can solve this problem, but requires the branch/sink to support HBlank reduction. [How] Update DPMS sequence to call DM to perform DPCD write to enable HBlank reduction on the branch/sink. Add stub in dm_helpers to be implemented later. Reviewed-by: Michael Strauss Reviewed-by: Wenjing Liu Signed-off-by: George Shen Signed-off-by: Roman Li Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd: Sanity check the ACPI EDID

2024-12-02T23:34:43Z

An HP Pavilion Aero Laptop 13-be0xxx/8916 has an ACPI EDID, but using it is causing corruption. It's got illogical values of not specifying a digital interface. Sanity check the ACPI EDID to avoid tripping such problems. Suggested-by: Tobias Jakobi Reported-and-tested-by: Chris Bainbridge Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3782 Fixes: c6a837088bed ("drm/amd/display: Fetch the EDID from _DDC if available for eDP") Reviewed-by: Harry Wentland Link: https://lore.kernel.org/r/20241128032500.2088288-1-superm1@kernel.org Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher

drm/amd/display: temp w/a for DP Link Layer compliance

2024-10-22T21:50:38Z

[Why&How] Disabling P-State support on full updates for DCN401 results in introducing additional communication with SMU. A UCLK hard min message to SMU takes 4 seconds to go through, which was due to DCN not allowing pstate switch, which was caused by incorrect value for TTU watermark before blanking the HUBP prior to DPG on for servicing the test request. Fix the issue temporarily by disallowing pstate changes for compliance test while test request handler is reworked for a proper fix. Fixes: 67ea53a4bd9d ("drm/amd/display: Disable DCN401 UCLK P-State support on full updates") Cc: Mario Limonciello Cc: Alex Deucher Reviewed-by: Dillon Varone Signed-off-by: Aurabindo Pillai Signed-off-by: Wayne Lin Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Check returns from drm_dp_dpcd_write

2024-10-15T15:22:33Z

[WHAT & HOW] drm_dp_dpcd_write() returns negative error on failure and thus returned values need to be checked. This fixes 3 UNUSED_VALUE issues reported by Coverity. Reviewed-by: Rodrigo Siqueira Signed-off-by: Alex Hung Signed-off-by: Roman Li Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Fetch the EDID from _DDC if available for eDP

2024-10-07T18:32:08Z

Some manufacturers have intentionally put an EDID that differs from the EDID on the internal panel on laptops. Attempt to fetch this EDID if it exists and prefer it over the EDID that is provided by the panel. If a user prefers to use the EDID from the panel, offer a DC debugging parameter that would disable this. Signed-off-by: Mario Limonciello Reviewed-by: Alex Hung Tested-by: Daniel Wheeler Signed-off-by: Rodrigo Siqueira Signed-off-by: Alex Deucher