72f1de49ff
[Why] The sequence for collecting down_reply from source perspective should be: Request_n->repeat (get partial reply of Request_n->clear message ready flag to ack DPRX that the message is received) till all partial replies for Request_n are received->new Request_n+1. Now there is chance that drm_dp_mst_hpd_irq() will fire new down request in the tx queue when the down reply is incomplete. Source is restricted to generate interveleaved message transactions so we should avoid it. Also, while assembling partial reply packets, reading out DPCD DOWN_REP Sideband MSG buffer + clearing DOWN_REP_MSG_RDY flag should be wrapped up as a complete operation for reading out a reply packet. Kicking off a new request before clearing DOWN_REP_MSG_RDY flag might be risky. e.g. If the reply of the new request has overwritten the DPRX DOWN_REP Sideband MSG buffer before source writing one to clear DOWN_REP_MSG_RDY flag, source then unintentionally flushes the reply for the new request. Should handle the up request in the same way. [How] Separete drm_dp_mst_hpd_irq() into 2 steps. After acking the MST IRQ event, driver calls drm_dp_mst_hpd_irq_send_new_request() and might trigger drm_dp_mst_kick_tx() only when there is no on going message transaction. Changes since v1: * Reworked on review comments received -> Adjust the fix to let driver explicitly kick off new down request when mst irq event is handled and acked -> Adjust the commit message Changes since v2: * Adjust the commit message * Adjust the naming of the divided 2 functions and add a new input parameter "ack". * Adjust code flow as per review comments. Changes since v3: * Update the function description of drm_dp_mst_hpd_irq_handle_event Changes since v4: * Change ack of drm_dp_mst_hpd_irq_handle_event() to be an array align the size of esi[] Signed-off-by: Wayne Lin <Wayne.Lin@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Alex Deucher <alexander.deucher@amd.com> |
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| .. | ||
| drm_dp_aux_bus.h | ||
| drm_dp_dual_mode_helper.h | ||
| drm_dp_helper.h | ||
| drm_dp_mst_helper.h | ||
| drm_dp.h | ||
| drm_dsc_helper.h | ||
| drm_dsc.h | ||
| drm_hdcp_helper.h | ||
| drm_hdcp.h | ||
| drm_hdmi_helper.h | ||
| drm_scdc_helper.h | ||
| drm_scdc.h | ||