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Commit 613b0e48 authored by Domi Papoi's avatar Domi Papoi Committed by Gerrit - the friendly Code Review server
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msm: BA: Fix a race condition in BA event handling 



Add proper locking in event handling so that invocation
of multiple events will not corrupt the event list.

Change-Id: I4499b3c0a106cbada54bbc122bb03ad5c30ed2c3
Signed-off-by: default avatarDomi Papoi <dpapoi@codeaurora.org>
parent ee86fb3c

drivers/video/msm/ba/msm_ba.c

+2 −0
Original line number Diff line number Diff line
@@ -736,7 +736,9 @@ void msm_ba_subdev_event_hndlr(struct v4l2_subdev *sd, 


	ba_sd_event->sd_event = *(struct v4l2_event *)arg;

	((int *)ba_sd_event->sd_event.u.data)[0] = ba_input->ba_ip_idx;

	mutex_lock(&dev_ctxt->dev_cs);

	list_add_tail(&ba_sd_event->list, &dev_ctxt->sd_events);

	mutex_unlock(&dev_ctxt->dev_cs);



	schedule_delayed_work(&dev_ctxt->sd_events_work, 0);

}

drivers/video/msm/ba/msm_ba_common.c

+4 −4
Original line number Diff line number Diff line 
/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.

/* Copyright (c) 2012-2016, 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
@@ -139,7 +139,6 @@ static void msm_ba_signal_sessions_event(struct v4l2_event *sd_event) 
	dev_ctxt = get_ba_dev();

	ptr = (unsigned int *)sd_event->u.data;



	mutex_lock(&dev_ctxt->dev_cs);

	list_for_each_entry(inst, &(dev_ctxt->instances), list) {

		if (inst->ext_ops && inst->ext_ops->msm_ba_cb) {

			arg = ptr[1];
@@ -149,7 +148,6 @@ static void msm_ba_signal_sessions_event(struct v4l2_event *sd_event) 
			msm_ba_queue_v4l2_event(inst, &event);

		}

	}

	mutex_unlock(&dev_ctxt->dev_cs);

}



void msm_ba_subdev_event_hndlr_delayed(struct work_struct *work)
@@ -160,17 +158,19 @@ void msm_ba_subdev_event_hndlr_delayed(struct work_struct *work) 


	dev_ctxt = get_ba_dev();



	mutex_lock(&dev_ctxt->dev_cs);

	if (!list_empty(&dev_ctxt->sd_events)) {

		list_for_each_entry_safe(ba_sd_event, ba_sd_event_tmp,

				&(dev_ctxt->sd_events), list) {

			list_del(&ba_sd_event->list);

			msm_ba_signal_sessions_event(&ba_sd_event->sd_event);

			list_del(&ba_sd_event->list);

			kfree(ba_sd_event);

			break;

		}

	} else {

		dprintk(BA_ERR, "%s - queue empty!!!", __func__);

	}

	mutex_unlock(&dev_ctxt->dev_cs);

}



struct v4l2_subdev *msm_ba_sd_find(const char *name)