kernel/linux.git/drivers/gpu/drm/amd/display/dc, branch v6.6.150

drm/amd/display: Fix dcn32 DTB DTO update breaking live pixel rate sources

2026-08-03T09:15:33+00:00

commit 76a2db58e95e328007043f54ac3c7336ccbee440 upstream. dcn32_update_clocks_update_dtb_dto() reprograms the DTB DTO of every timing generator in the context whenever the DTBCLK reference changes, passing a zeroed pixel rate and never setting is_hdmi. dccg32_set_dtbclk_dto() treats a zero pixel rate as a disable request, and that branch drives PIPE_DTO_SRC_SEL to the DP DTO source. A timing generator actively scanning out an HDMI stream therefore has its pixel rate source re-muxed out from under the live raster, and the OTG stops on the spot. Two displays where only one runs a 128b/132b link hit this reliably. is_dtbclk_required() holds the DTBCLK reference high while both are active, and the moment the 128b/132b stream is torn down (compositor switch, display disable, hot-unplug) the next safe_to_lower pass drops the reference to the lowest DPM level and the DTO walk freezes the surviving screen. On Navi31 the DAL mailbox then goes deaf on the DISPCLK hard-min that follows the walk in dcn32_update_clocks(), stranding both SMU mailboxes until reboot. Set is_hdmi for HDMI and DVI signals so the disable path leaves the pixel rate source selection on the HDMI path, and pass the real pixel rate for 128b/132b streams so a reference change rescales their DTO instead of disabling it. Fixes: 128c1ca0303f ("drm/amd/display: Update DTBCLK for DCN32") Signed-off-by: Harry Wentland Reviewed-by: Fangzhi Zuo Tested-by: Dan Wheeler Signed-off-by: Alex Deucher [ mschwartz: dcn32 clk_mgr hunk only, as 6.6.y predates the dcn35 clk_mgr. The rest is HDMI FRL enablement, absent before 7.2, so the FRL conditions and the req_audio_dtbclk_khz assignment they guard are dropped and the FRL-centric changelog is rewritten. Added the pipe_ctx->stream check the new dereferences need. ] Signed-off-by: Matthew Schwartz Signed-off-by: Sasha Levin

drm/amd/display: detect_link_and_local_sink: DP alt mode timeout path leaks prev_sink reference

2026-08-03T09:15:24+00:00

commit a6e14b976be48eebd8769cb5b883a6af7fc5ade1 upstream. prev_sink is unconditionally retained via dc_sink_retain at function entry, but the DP alt mode timeout path inside SIGNAL_TYPE_DISPLAY_PORT returns false without releasing prev_sink. All other return paths in the function correctly call dc_sink_release(prev_sink), making this the only missing cleanup. Fixes: 54618888d1ea ("drm/amd/display: break down dc_link.c") Signed-off-by: WenTao Liang Reviewed-by: Mario Limonciello (AMD) Link: https://patch.msgid.link/20260626124555.36910-1-vulab@iscas.ac.cn Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher (cherry picked from commit 45510cf662dcf46b5d8926d454f338809f107b9d) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

drm/amd: Fix set but not used warnings

2026-07-24T14:02:36+00:00

[ Upstream commit 46791d147d3ab3262298478106ef2a52fc7192e2 ] There are many set but not used warnings under drivers/gpu/drm/amd when compiling with the latest upstream mainline GCC: drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c:305:18: warning: variable ‘p’ set but not used [-Wunused-but-set-variable=] drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h:103:26: warning: variable ‘internal_reg_offset’ set but not used [-Wunused-but-set-variable=] ... drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h:164:26: warning: variable ‘internal_reg_offset’ set but not used [-Wunused-but-set-variable=] ... drivers/gpu/drm/amd/amdgpu/../display/dc/dc_dmub_srv.c:445:13: warning: variable ‘pipe_idx’ set but not used [-Wunused-but-set-variable=] drivers/gpu/drm/amd/amdgpu/../display/dc/dc_dmub_srv.c:875:21: warning: variable ‘pipe_idx’ set but not used [-Wunused-but-set-variable=] Remove the variables actually not used or add __maybe_unused attribute for the variables actually used to fix them, compile tested only. Signed-off-by: Tiezhu Yang Signed-off-by: Alex Deucher Signed-off-by: Ron Economos Signed-off-by: Sasha Levin

drm/amd/display: Bound VBIOS record-chain walk loops

2026-07-04T11:42:18+00:00

[ Upstream commit ff287df16a1a58aca78b08d1f3ee09fc44da0351 ] [Why & How] All record-chain walk loops in bios_parser.c and bios_parser2.c use for(;;) and only terminate on a 0xFF record_type sentinel or zero record_size. A malformed VBIOS image missing the terminator record causes unbounded iteration at probe time, potentially hundreds of thousands of iterations with record_size=1. In the final iterations near the BIOS image boundary, struct casts beyond the 2-byte header validated by GET_IMAGE can also read out of bounds. Cap all 14 record-chain walk loops to BIOS_MAX_NUM_RECORD (256) iterations. The atombios.h defines up to 22 distinct record types and atomfirmware.h has 13. Assuming an average of less than 10 records per type (which is reasonable since most are connector- based) 256 is a generous upper bound. Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)") Assisted-by: Copilot:claude-opus-4.6 Mythos Reviewed-by: Alex Hung Signed-off-by: Harry Wentland Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 95700a3d660287ed657d6892f7be9ffc0e294a93) Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

drm/amd/display: Use krealloc_array() in dal_vector_reserve()

2026-06-19T11:39:37+00:00

commit da48bc4461b8a5ebfb9264c9b191a701d8e99009 upstream. [Why & How] dal_vector_reserve() computes the allocation size as "capacity * vector->struct_size" using uint32_t arithmetic, which can silently wrap to a small value on overflow. This would cause krealloc to return a smaller buffer than expected, leading to heap overflows on subsequent vector appends. Replace krealloc() with krealloc_array() which performs an internal overflow check and returns NULL on wrap, preventing the issue. Fixes: 2004f45ef83f ("drm/amd/display: Use kernel alloc/free") 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 (cherry picked from commit 37668568641ccc4cc1dbca4923d0a16609dd5707) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Clamp VBIOS HDMI retimer register count to array size

2026-06-19T11:39:37+00:00

commit fb0707ce00eef4e2d60c3020e1c0432739703e4a upstream. [Why & How] The VBIOS integrated info tables (v1_11 and v2_1) contain HdmiRegNum and Hdmi6GRegNum fields that are used as loop bounds when copying retimer I2C register settings into fixed-size arrays (dp*_ext_hdmi_reg_settings[9] and dp*_ext_hdmi_6g_reg_settings[3]). These u8 fields are not validated before use, so a malformed VBIOS can specify values up to 255, causing an out-of-bounds heap write during driver probe. Clamp each register count to the destination array size using min_t() before the copy loops, in both get_integrated_info_v11() and get_integrated_info_v2_1(). Assisted-by: GitHub 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 (cherry picked from commit 5a7f0ef90195940c54b0f5bb85b87da55f038c69) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Reject gpio_bitshift >= 32 in bios_parser_get_gpio_pin_info()

2026-06-19T11:39:33+00:00

commit 49c3da65961fe9857c831d47fa1989084e87514a upstream. [Why & How] gpio_bitshift is a uint8_t read directly from the VBIOS GPIO pin table. If the value is >= 32, the expression "1 << gpio_bitshift" triggers undefined behaviour in C (shift count exceeds type width). On x86 the shift is silently masked to 5 bits, producing an incorrect GPIO mask that may cause wrong MMIO register bits to be toggled. Validate gpio_bitshift before use and return BP_RESULT_BADBIOSTABLE for out-of-range values. Fixes: ae79c310b1a6 ("drm/amd/display: Add DCE12 bios parser support") 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 (cherry picked from commit eadf438ab8d370b9d19acee9359918c85afeb80d) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async

2026-06-01T15:43:09+00:00

commit 6c92f6d9600efa3ef0d9e560a2b52776d9803c29 upstream. [Why&How] dc_process_dmub_aux_transfer_async() copies payload->length bytes into a 16-byte stack buffer (dpaux.data[16]) guarded only by an ASSERT(), which is a no-op in release builds. If a caller ever passes length > 16 this results in a stack buffer overflow via memcpy. Additionally, link_index is used to dereference dc->links[] without bounds checking against dc->link_count, risking an out-of-bounds access. Replace the ASSERT with a hard runtime check that returns false when payload->length exceeds the destination buffer size, and add a bounds check for link_index before it is used. Assisted-by: GitHub Copilot:Claude claude-4-opus Reviewed-by: Alex Hung Signed-off-by: Harry Wentland Signed-off-by: Ivan Lipski Tested-by: Dan Wheeler Signed-off-by: Alex Deucher (cherry picked from commit ba4caa9fecdf7a38f98c878ad05a8a64148b6881) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Validate GPIO pin LUT table size before iterating

2026-06-01T15:43:09+00:00

commit 86d2b20644b11d21fe52c596e6e922b4590a3e3f upstream. [Why&How] The GPIO pin table parsers in get_gpio_i2c_info() and bios_parser_get_gpio_pin_info() derive an element count from the VBIOS table_header.structuresize field, then iterate over gpio_pin[] entries. However, GET_IMAGE() only validates that the table header itself fits within the BIOS image. If the VBIOS reports a structuresize larger than the actual mapped data, the loop reads past the end of the BIOS image, causing an out-of-bounds read. Fix this by calling bios_get_image() to validate that the full claimed structuresize is accessible within the BIOS image before entering the loop in both functions. Assisted-by: GitHub Copilot:claude-opus-4-6 Reviewed-by: Alex Hung Signed-off-by: Harry Wentland Signed-off-by: Ivan Lipski Tested-by: Dan Wheeler Signed-off-by: Alex Deucher (cherry picked from commit ba5e95b43b773ae1bf1f66ee6b31eb774e65afe3) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Fix integer overflow in bios_get_image()

2026-06-01T15:43:09+00:00

commit cd86529ec61474a38c3837fb7823790a7c3f8cce upstream. [Why&How] The bounds check in bios_get_image() computes 'offset + size' using unsigned 32-bit arithmetic before comparing against bios_size. If a VBIOS image contains a near-UINT32_MAX offset the addition wraps to a small value, the comparison passes, and the function returns a wild pointer past the VBIOS mapping. Additionally, the comparison uses '<' (strict), which incorrectly rejects the valid exact-fit case where offset + size == bios_size. Fix both issues by restructuring the check to avoid the addition entirely: first reject if offset alone exceeds bios_size, then check size against the remaining space (bios_size - offset). This eliminates the overflow and correctly permits exact-fit accesses. Assisted-by: GitHub Copilot:claude-opus-4.6 Reviewed-by: Alex Hung Signed-off-by: Harry Wentland Signed-off-by: Ivan Lipski Tested-by: Dan Wheeler Signed-off-by: Alex Deucher (cherry picked from commit d40fb392af659c4a02b560319f226842f6ec1a95) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman