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Commit aee5aeb2 authored by Govinda Rajulu Chenna's avatar Govinda Rajulu Chenna Committed by Gerrit - the friendly Code Review server
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drm/msm/dp: avoid mst_hpd_irq process before mst session start 



Processing mst_hpd_irq before mst session start, that is mst_hpd,
leads in accessing uninitialized mst data structures. This change
verifies the mst session start state before processing mst_hpd_irq.

CRs-Fixed: 2372565
Change-Id: I75f568ca05a8f0d80c7a4fe890013c374baf3c15
Signed-off-by: default avatarGovinda Rajulu Chenna <gchenna@codeaurora.org>
parent 69e70152

drivers/gpu/drm/msm/dp/dp_mst_drm.c

+11 −1
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2018, The Linux Foundation. All rights reserved.

 * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and
@@ -123,6 +123,7 @@ struct dp_mst_private { 
	struct dp_mst_sim_mode simulator;

	struct mutex mst_lock;

	enum dp_drv_state state;

	bool mst_session_state;

};



struct dp_mst_encoder_info_cache {
@@ -1473,6 +1474,10 @@ static void dp_mst_display_hpd(void *dp_display, bool hpd_status, 
	struct dp_display *dp = dp_display;

	struct dp_mst_private *mst = dp->dp_mst_prv_info;



	mutex_lock(&mst->mst_lock);

	mst->mst_session_state = hpd_status;

	mutex_unlock(&mst->mst_lock);



	if (!hpd_status)

		rc = mst->mst_fw_cbs->topology_mgr_set_mst(&mst->mst_mgr,

				hpd_status);
@@ -1511,6 +1516,11 @@ static void dp_mst_display_hpd_irq(void *dp_display, 
		return;

	}



	if (!mst->mst_session_state) {

		pr_err("mst_hpd_irq received before mst session start\n");

		return;

	}



	rc = drm_dp_dpcd_read(mst->caps.drm_aux, DP_SINK_COUNT_ESI,

		esi, 14);

	if (rc != 14) {