kernel.git/drivers/gpu/drm/msm/dp, branch linux-6.16.y

drm/msm/dp: Disable wide bus support for SDM845

2025-06-08T22:31:42Z

When widebus was enabled for DisplayPort in commit c7c412202623 ("drm/msm/dp: enable widebus on all relevant chipsets") it was clarified that it is only supported on DPU 5.0.0 onwards which includes SC7180 on DPU revision 6.2. However, this patch missed that the description structure for SC7180 is also reused for SDM845 (because of identical io_start address) which is only DPU 4.0.0, leading to a wrongly enbled widebus feature and corruption on that platform. Create a separate msm_dp_desc_sdm845 structure for this SoC compatible, with the wide_bus_supported flag turned off. Fixes: c7c412202623 ("drm/msm/dp: enable widebus on all relevant chipsets") Signed-off-by: James A. MacInnes [DB: reworded commit text following Marijn's suggestion] Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/636944/ Link: https://lore.kernel.org/r/20250212-sdm845_dp-v2-1-4954e51458f4@gmail.com Signed-off-by: Dmitry Baryshkov

drm/msm/dp: Introduce link training per-segment for LTTPRs

2025-05-12T16:18:49Z

DisplayPort requires per-segment link training when LTTPR are switched to non-transparent mode, starting with LTTPR closest to the source. Only when each segment is trained individually, source can link train to sink. Implement per-segment link traning when LTTPR(s) are detected, to support external docking stations. On higher level, changes are: * Pass phy being trained down to all required helpers * Run CR, EQ link training per phy * Set voltage swing, pre-emphasis levels per phy Since at least some LTTPRs (eg. Parade PS8830) do not correctly report voltage-swing, pre-emphasis level 3 support, always assume level 3 is supported. This is permitted under DP 2.1(a) section 3.6.7.2 stating that LTTPR shall set its transmitter levels as close as possible to those requested by the DPTX, if the DPTX sets the voltage swing or pre-emphasis to a level that the LTTPR does not support. It shall be noted that LTTPR’s level choosing is implementation-specific. This ensures successful link training both when connected directly to the monitor (single LTTPR onboard most X1E laptops) and via the docking station (at least two LTTPRs). Fixes: 72d0af4accd9 ("drm/msm/dp: Add support for LTTPR handling") Tested-by: Jessica Zhang # SA8775P Tested-by: Johan Hovold Tested-by: Rob Clark Tested-by: Stefan Schmidt Signed-off-by: Aleksandrs Vinarskis Reviewed-by: Abel Vesa Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/652305/ Link: https://lore.kernel.org/r/20250507230113.14270-5-alex.vinarskis@gmail.com Signed-off-by: Dmitry Baryshkov

drm/msm/dp: Prepare for link training per-segment for LTTPRs

2025-05-12T16:18:49Z

Per-segment link training requires knowing the number of LTTPRs (if any) present. Store the count during LTTPRs' initialization. Fixes: 72d0af4accd9 ("drm/msm/dp: Add support for LTTPR handling") Reviewed-by: Abel Vesa Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Aleksandrs Vinarskis Tested-by: Jessica Zhang # SA8775P Tested-by: Johan Hovold Tested-by: Rob Clark Patchwork: https://patchwork.freedesktop.org/patch/652306/ Link: https://lore.kernel.org/r/20250507230113.14270-4-alex.vinarskis@gmail.com Signed-off-by: Dmitry Baryshkov

drm/msm/dp: Account for LTTPRs capabilities

2025-05-12T16:18:49Z

Take into account LTTPR capabilities when selecting maximum allowed link rate, number of data lines. Fixes: 72d0af4accd9 ("drm/msm/dp: Add support for LTTPR handling") Reviewed-by: Abel Vesa Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Aleksandrs Vinarskis Tested-by: Jessica Zhang # SA8775P Tested-by: Johan Hovold Tested-by: Rob Clark Patchwork: https://patchwork.freedesktop.org/patch/652302/ Link: https://lore.kernel.org/r/20250507230113.14270-3-alex.vinarskis@gmail.com Signed-off-by: Dmitry Baryshkov

drm/msm/dp: Fix support of LTTPR initialization

2025-05-12T16:18:49Z

Initialize LTTPR before msm_dp_panel_read_sink_caps, as DPTX shall (re)read DPRX caps after LTTPR detection, as required by DP 2.1a, Section 3.6.7.6.1. Fixes: 72d0af4accd9 ("drm/msm/dp: Add support for LTTPR handling") Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Aleksandrs Vinarskis Tested-by: Jessica Zhang # SA8775P Tested-by: Johan Hovold Tested-by: Rob Clark Patchwork: https://patchwork.freedesktop.org/patch/652301/ Link: https://lore.kernel.org/r/20250507230113.14270-2-alex.vinarskis@gmail.com Signed-off-by: Dmitry Baryshkov

drm/msm/dp: reuse generic HDMI codec implementation

2025-05-02T00:54:03Z

The MSM DisplayPort driver implements several HDMI codec functions in the driver, e.g. it manually manages HDMI codec device registration, returning ELD and plugged_cb support. In order to reduce code duplication reuse drm_hdmi_audio_* helpers and drm_bridge_connector integration. Signed-off-by: Dmitry Baryshkov Signed-off-by: Dmitry Baryshkov Reviewed-by: Abhinav Kumar Patchwork: https://patchwork.freedesktop.org/patch/649728/ Link: https://lore.kernel.org/r/20250423-dp-hdmi-audio-v7-1-8407a23e55b2@oss.qualcomm.com

drm/msm/dp: convert to devm_drm_bridge_alloc() API

2025-04-29T09:21:24Z

This is the new API for allocating DRM bridges. Reviewed-by: Dmitry Baryshkov Signed-off-by: Luca Ceresoli Link: https://patchwork.freedesktop.org/patch/msgid/20250424-drm-bridge-convert-to-alloc-api-v2-16-8f91a404d86b@bootlin.com Signed-off-by: Louis Chauvet

Merge drm/drm-next into drm-misc-next

2025-04-07T12:35:48Z

Backmerging to get v6.15-rc1 into drm-misc-next. Also fixes a build issue when enabling CONFIG_DRM_SCHED_KUNIT_TEST. Signed-off-by: Thomas Zimmermann

drm/display: dp: change drm_dp_dpcd_read_link_status() return value

2025-03-25T14:20:38Z

drm_dp_dpcd_read_link_status() follows the "return error code or number of bytes read" protocol, with the code returning less bytes than requested in case of some errors. However most of the drivers interpreted that as "return error code in case of any error". Switch drm_dp_dpcd_read_link_status() to drm_dp_dpcd_read_data() and make it follow that protocol too. Acked-by: Jani Nikula Reviewed-by: Lyude Paul Signed-off-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20250324-drm-rework-dpcd-access-v4-2-e80ff89593df@oss.qualcomm.com Signed-off-by: Dmitry Baryshkov

drm/msm: Use str_enable_disable-like helpers

2025-02-25T18:07:44Z

Replace ternary (condition ? "enable" : "disable") syntax with helpers from string_choices.h because: 1. Simple function call with one argument is easier to read. Ternary operator has three arguments and with wrapping might lead to quite long code. 2. Is slightly shorter thus also easier to read. 3. It brings uniformity in the text - same string. 4. Allows deduping by the linker, which results in a smaller binary file. Signed-off-by: Krzysztof Kozlowski Reviewed-by: Abhinav Kumar Patchwork: https://patchwork.freedesktop.org/patch/632406/ Link: https://lore.kernel.org/r/20250114191724.861601-1-krzysztof.kozlowski@linaro.org Signed-off-by: Dmitry Baryshkov