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[1/2] media: au0828 fix to protect enable/disable source set and clear

Message ID 6a4776ad1450ecf6ce73e5c005e0549fc29e7710.1480384155.git.shuahkh@osg.samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Shuah Khan Nov. 29, 2016, 2:15 a.m. UTC 
Protect enable/disable source set and clear to avoid races with callers.
There is a possibility clear could occur while dvb-core and v4l2 try to
access these handlers.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
 drivers/media/usb/au0828/au0828-core.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox

Patch

diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
index bf53553..a1f696a 100644
--- a/drivers/media/usb/au0828/au0828-core.c
+++ b/drivers/media/usb/au0828/au0828-core.c
@@ -153,9 +153,11 @@  static void au0828_unregister_media_device(struct au0828_dev *dev)
 	}
 
 	/* clear enable_source, disable_source */
+	mutex_lock(&mdev->graph_mutex);
 	dev->media_dev->source_priv = NULL;
 	dev->media_dev->enable_source = NULL;
 	dev->media_dev->disable_source = NULL;
+	mutex_unlock(&mdev->graph_mutex);
 
 	media_device_unregister(dev->media_dev);
 	media_device_cleanup(dev->media_dev);
@@ -549,9 +551,11 @@  static int au0828_media_device_register(struct au0828_dev *dev,
 		return ret;
 	}
 	/* set enable_source */
+	mutex_lock(&dev->media_dev->graph_mutex);
 	dev->media_dev->source_priv = (void *) dev;
 	dev->media_dev->enable_source = au0828_enable_source;
 	dev->media_dev->disable_source = au0828_disable_source;
+	mutex_unlock(&dev->media_dev->graph_mutex);
 #endif
 	return 0;
 }