kernel/linux.git/drivers/gpu/drm/msm/dp, branch v6.19.12

drm/msm/dp: Avoid division by zero in msm_dp_ctrl_config_msa()

2026-02-26T23:01:01+00:00

[ Upstream commit f185076da44c774241a16a82a7773ece3c1c607b ] An (admittedly problematic) optimization change in LLVM 20 [1] turns known division by zero into the equivalent of __builtin_unreachable(), which invokes undefined behavior if it is encountered in a control flow graph, destroying code generation. When compile testing for x86_64, objtool flags an instance of this optimization triggering in msm_dp_ctrl_config_msa(), inlined into msm_dp_ctrl_on_stream(): drivers/gpu/drm/msm/msm.o: warning: objtool: msm_dp_ctrl_on_stream(): unexpected end of section .text.msm_dp_ctrl_on_stream The zero division happens if the else branch in the first if statement in msm_dp_ctrl_config_msa() is taken because pixel_div is initialized to zero and it is not possible for LLVM to eliminate the else branch since rate is still not known after inlining into msm_dp_ctrl_on_stream(). Transform the if statements into a switch statement with a default case with the existing error print and an early return to avoid the invalid division. Add a comment to note this helps the compiler, even though the case is known to be unreachable. With this, pixel_dev's default zero initialization can be dropped, as it is dead with this change. Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support") Link: https://github.com/llvm/llvm-project/commit/37932643abab699e8bb1def08b7eb4eae7ff1448 [1] Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202601081959.9UVJEOfP-lkp@intel.com/ Suggested-by: Konrad Dybcio Signed-off-by: Nathan Chancellor Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/698355/ Link: https://lore.kernel.org/r/20260113-drm-msm-dp_ctrl-avoid-zero-div-v2-1-f1aa67bf6e8e@kernel.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dp: Update msm_dp_controller IDs for sa8775p

2026-02-26T23:00:59+00:00

[ Upstream commit 1338e8ae4084e55c0359a79e617b2ae183d01579 ] The Qualcomm SA8775P platform comes with 2 DisplayPort controllers for each mdss. Update controller id for DPTX0 and DPTX1 of mdss1. Fixes: dcb380d19e58 ("drm/msm/dp: Add DisplayPort controller for SA8775P") Signed-off-by: Mani Chandana Ballary Kuntumalla Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/690234/ Link: https://lore.kernel.org/r/20251125105622.1755651-2-quic_mkuntuma@quicinc.com Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dp: fix all kernel-doc warnings

2025-12-24T09:24:18+00:00

Correct and add kernel-doc comments to eliminate all warnings: Warning: ../drivers/gpu/drm/msm/dp/dp_debug.h:31 expecting prototype for msm_dp_debug_get(). Prototype was for msm_dp_debug_init() instead Warning: ../drivers/gpu/drm/msm/dp/dp_drm.c:24 function parameter 'connector' not described in 'msm_dp_bridge_detect' Warning: ../drivers/gpu/drm/msm/dp/dp_link.h:90 expecting prototype for mdss_dp_test_bit_depth_to_bpp(). Prototype was for msm_dp_link_bit_depth_to_bpp() instead Warning: ../drivers/gpu/drm/msm/dp/dp_link.h:126 function parameter 'aux' not described in 'msm_dp_link_get' Warning: ../drivers/gpu/drm/msm/dp/dp_link.h:126 function parameter 'dev' not described in 'msm_dp_link_get' Warning: ../drivers/gpu/drm/msm/dp/dp_panel.h:70 function parameter 'bw_code' not described in 'is_link_rate_valid' Warning: ../drivers/gpu/drm/msm/dp/dp_panel.h:84 expecting prototype for msm_dp_link_is_lane_count_valid(). Prototype was for is_lane_count_valid() instead Signed-off-by: Randy Dunlap Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/695647/ Link: https://lore.kernel.org/r/20251219184638.1813181-3-rdunlap@infradead.org Signed-off-by: Dmitry Baryshkov

drm/msm/dp: Add support for Glymur

2025-11-14T14:59:27+00:00

The Qualcomm Glymur platform comes with 4 DisplayPort controllers, which have a different core revision compared to all previous platforms. Describe them and add the compatible. Reviewed-by: Dmitry Baryshkov Signed-off-by: Abel Vesa Patchwork: https://patchwork.freedesktop.org/patch/683722/ Link: https://lore.kernel.org/r/20251027-glymur-display-v3-6-aa13055818ac@linaro.org Signed-off-by: Dmitry Baryshkov

drm/msm/dp: Add support for lane mapping configuration

2025-11-14T14:59:27+00:00

QCS615 platform requires non-default logical-to-physical lane mapping due to its unique hardware routing. Unlike the standard mapping sequence <0 1 2 3>, QCS615 uses <3 2 0 1>, which necessitates explicit configuration via the data-lanes property in the device tree. This ensures correct signal routing between the DP controller and PHY. For partial definitions, fill remaining lanes with unused physical lanes in ascending order. Signed-off-by: Xiangxu Yin Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/675645/ Link: https://lore.kernel.org/r/20250919-add-displayport-support-for-qcs615-platform-v5-14-eae6681f4002@oss.qualcomm.com Signed-off-by: Dmitry Baryshkov

drm/msm/dp: move link-specific parsing from dp_panel to dp_link

2025-11-14T14:59:27+00:00

Since max_dp_lanes and max_dp_link_rate are link-specific parameters, move their parsing from dp_panel to dp_link for better separation of concerns. Reviewed-by: Dmitry Baryshkov Signed-off-by: Xiangxu Yin Patchwork: https://patchwork.freedesktop.org/patch/675643/ Link: https://lore.kernel.org/r/20250919-add-displayport-support-for-qcs615-platform-v5-13-eae6681f4002@oss.qualcomm.com Signed-off-by: Dmitry Baryshkov

drm/bridge: Pass down connector to drm bridge detect hook

2025-07-14T15:23:18+00:00

In some application scenarios, we hope to get the corresponding connector when the bridge's detect hook is invoked. In most cases, we can get the connector by drm_atomic_get_connector_for_encoder if the encoder attached to the bridge is enabled, however there will still be some scenarios where the detect hook of the bridge is called but the corresponding encoder has not been enabled yet. For instance, this occurs when the device is hot plug in for the first time. Since the call to bridge's detect is initiated by the connector, passing down the corresponding connector directly will make things simpler. Signed-off-by: Andy Yan Reviewed-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20250703125027.311109-3-andyshrk@163.com [DB: added the chunk to the cdn-dp driver] Signed-off-by: Dmitry Baryshkov

drm/bridge: Make dp/hdmi_audio_* callback keep the same paramter order with get_modes

2025-07-14T15:23:18+00:00

Make the dp/hdmi_audio_* callback maintain the same parameter order as get_modes and edid_read: first the bridge, then the connector. Signed-off-by: Andy Yan Reviewed-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20250703125027.311109-2-andyshrk@163.com [DB: added the chunk to the cdn-dp driver] Signed-off-by: Dmitry Baryshkov

drm/msm: make it possible to disable KMS-related code.

2025-07-05T14:13:35+00:00

If the Adreno device is used in a headless mode, there is no need to build all KMS components. Build corresponding parts conditionally, only selecting them if modeset support is actually required. Signed-off-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/662581/ Signed-off-by: Rob Clark

drm/msm: move KMS driver data to msm_kms

2025-07-05T14:13:35+00:00

Data for HDMI, DSI and DP blocks only makes sense for the KMS parts of the driver. Move corresponding data pointers from struct msm_drm_private to struct msm_kms. Suggested-by: Abhinav Kumar Signed-off-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/662580/ Signed-off-by: Rob Clark