When em28xx extensions are loaded/removed, there are two locks:
a single static em28xx_devlist_mutex that registers each extension
and the struct em28xx dev->lock.
When extensions are registered, em28xx_devlist_mutex is taken first,
and then dev->lock.
Be sure that, when extensions are being removed, the same order
will be used.
Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
---
drivers/media/usb/em28xx/em28xx-cards.c | 5 +++--
drivers/media/usb/em28xx/em28xx-core.c | 2 ++
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index 4fe742429f2c..36aec50e5c3b 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3334,9 +3334,7 @@ static void em28xx_usb_disconnect(struct usb_interface *interface)
dev->disconnected = 1;
if (dev->is_audio_only) {
- mutex_lock(&dev->lock);
em28xx_close_extension(dev);
- mutex_unlock(&dev->lock);
return;
}
@@ -3355,10 +3353,13 @@ static void em28xx_usb_disconnect(struct usb_interface *interface)
em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
em28xx_uninit_usb_xfer(dev, EM28XX_DIGITAL_MODE);
}
+ mutex_unlock(&dev->lock);
em28xx_close_extension(dev);
+
/* NOTE: must be called BEFORE the resources are released */
+ mutex_lock(&dev->lock);
if (!dev->users)
em28xx_release_resources(dev);
diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c
index 2ad84ff1fc4f..97cc83c3c287 100644
--- a/drivers/media/usb/em28xx/em28xx-core.c
+++ b/drivers/media/usb/em28xx/em28xx-core.c
@@ -1097,10 +1097,12 @@ void em28xx_close_extension(struct em28xx *dev)
const struct em28xx_ops *ops = NULL;
mutex_lock(&em28xx_devlist_mutex);
+ mutex_lock(&dev->lock);
list_for_each_entry(ops, &em28xx_extension_devlist, next) {
if (ops->fini)
ops->fini(dev);
}
+ mutex_unlock(&dev->lock);
list_del(&dev->devlist);
mutex_unlock(&em28xx_devlist_mutex);
}
--
1.8.3.1
--
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