Currently, all HPD interrupt handling must go through the HPD state machine.
This has caused many issues where the DRM framework assumes that DP is in one state while the state machine is stuck in another state. As discussed here [1], this series: - Removes the state machine - Moves link training to atomic_enable() - Changes the detect() behavior to return true if a display is physically plugged in (as opposed to if the DP link is ready). - Remove event queue and move internal HPD handling to hpd_notify() To correctly detect the displays which are plugged on boot on the boards which use dp-connector devices, this series depends on [2]. USB-C and eDP panels are handled natively. [1] https://patchwork.freedesktop.org/patch/656312/?series=142010&rev=2#comment_1201738 [2] https://lore.kernel.org/all/[email protected]/ --- Changes in v6: - Corrected mismatch between Jessica's From and SoB emails - Corrected documentation and fixed style comments for msm_dp_bridge_detect() (Bjorn, Konrad) - Changed msm_dp_bridge_atomic_enable() to bail out earlier in case of link training failure (Konrad) - Corrected commit message for the link training commit to stop mentioning event-related changes (Konrad) - Added kerneldoc to msm_dp_display_host_phy_init(), describing return value (Konrad) - Switched to guard() instead of raw mutex_lock() (Konrad) - Link to v5: https://lore.kernel.org/r/[email protected] Changes in v5: - Fixed the EDID clearing on display unplug - Fixed the initial HPD issue via the external series - Tested on eDP devices - Link to v4: https://lore.kernel.org/r/[email protected] Changes in v4: - Fixed PM runtime handling - Fixed several cases where the HPD machine would loose its state - Fixed the case where detection was ignoring the plugging in display. - Link to v3: https://lore.kernel.org/r/[email protected] Changes in v3: - Take over the series (thanks, Jessica, for the previous work!) - Major rework of the series, squashed the set of patches touching the HPD states and handling, it is easier to do it this way rather than pulling the strings one by one. - Link to v2: https://lore.kernel.org/r/[email protected] Changes in v2: - Dropped event queue (Dmitry) - Moved internal HPD handling to use hpd_notify() (Dmitry) - Reworked bridge detect() to read DPCP and sink count (Dmitry) - Moved setting of link_trained to plug/unplugged handling - Dropped msm_dp::connected (Dmitry) - Squashed all hpd state related patches (Dmitry) - Link to v1: https://lore.kernel.org/r/[email protected] To: Rob Clark <[email protected]> To: Dmitry Baryshkov <[email protected]> To: Abhinav Kumar <[email protected]> To: Jessica Zhang <[email protected]> To: Sean Paul <[email protected]> To: Marijn Suijten <[email protected]> To: David Airlie <[email protected]> To: Simona Vetter <[email protected]> To: Kuogee Hsieh <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] --- Dmitry Baryshkov (3): drm/msm/dp: drop event data drm/msm/dp: turn link_ready into plugged drm/msm/dp: clear EDID on display unplug Jessica Zhang (7): drm/msm/dp: fix HPD state status bit shift value drm/msm/dp: Fix the ISR_* enum values drm/msm/dp: Read DPCD and sink count in bridge detect() drm/msm/dp: Move link training to atomic_enable() drm/msm/dp: Drop EV_USER_NOTIFICATION drm/msm/dp: rework HPD handling drm/msm/dp: Add sink_count to debug logs drivers/gpu/drm/msm/dp/dp_ctrl.c | 16 - drivers/gpu/drm/msm/dp/dp_ctrl.h | 1 - drivers/gpu/drm/msm/dp/dp_display.c | 722 ++++++++++++------------------------ drivers/gpu/drm/msm/dp/dp_display.h | 3 +- drivers/gpu/drm/msm/dp/dp_drm.c | 63 +--- drivers/gpu/drm/msm/dp/dp_drm.h | 2 + drivers/gpu/drm/msm/dp/dp_panel.c | 8 + drivers/gpu/drm/msm/dp/dp_panel.h | 2 + drivers/gpu/drm/msm/dp/dp_reg.h | 4 +- 9 files changed, 255 insertions(+), 566 deletions(-) --- base-commit: 687da68900cd1a46549f7d9430c7d40346cb86a0 change-id: 20250523-hpd-refactor-74e25b55620a prerequisite-change-id: 20260314-dp-connector-hpd-f069e66bc6af:v2 prerequisite-patch-id: 90db75e3fb8bc9c81c67547db7bbd4eefd5d6c40 prerequisite-patch-id: 1c4d030b93a8cc6c98b3447a8685da24eb1f24d5 Best regards, -- With best wishes Dmitry
