From b1d43e6fb38fc24f8f673a465821aa58324df654 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Fri, 25 Oct 2024 19:02:52 +0300 Subject: drm/i915/dp: Flush modeset commits during connector detection MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make sure that a DP connector detection doesn't happen in parallel with an ongoing modeset on the connector. The reasons for this are: - Besides reading the capabilities, EDID etc. the detection may change the state of the sink (via the AUX bus), for instance by setting the LTTPR mode or the source OUI (the latter introduced by an upcoming patch). It's better to avoid such changes affecting an onging modeset in any way. - During a modeset's link training any access to DPCD registers, besides the registers used for link training should be avoided, at least in the LTTPR non-transparent and transparent link training modes. Such asynchronous accesses - besides connector detection - can also happen via the AUX device node for instance, for those a parallel modeset will have to be avoided in a similar way to the change in this patch. (A topic for a follow-up change.) - The source OUI written to an eDP sink is valid only while the panel power is enabled. A modeset on eDP will enable/disable the panel power synchronously; this should be prevented in the middle of the connector detection, to ensure a consistent sink state (which depends on the source OUI) for the whole duration of detection. The panel power could still get disabled during detection after an idle period (1 sec), this will be prevented by the next patch. v2: (Ville) - s/wait_for_crtc_hw_done/wait_for_connector_hw_done - Get drm_device using an intel_display instead of drm_i915_private ptr. Reviewed-by: Ville Syrjälä Signed-off-by: Imre Deak Link: https://patchwork.freedesktop.org/patch/msgid/20241025160259.3088727-2-imre.deak@intel.com --- drivers/gpu/drm/i915/display/intel_dp_mst.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/gpu/drm/i915/display/intel_dp_mst.c') diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 1a2ff3e1cb68..5bba078c00d8 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -1573,6 +1573,8 @@ intel_dp_mst_detect(struct drm_connector *connector, if (!intel_display_driver_check_access(i915)) return connector->status; + intel_dp_flush_connector_commits(intel_connector); + return drm_dp_mst_detect_port(connector, ctx, &intel_dp->mst_mgr, intel_connector->port); } -- cgit v1.2.3-70-g09d2