[PATCH] media: au0828: Convert BUG_ON to WARN_ONCE

From: Larry Finger
Date: Sun Apr 08 2012 - 19:20:19 EST


In the mail thread at http://www.mythtv.org/pipermail/mythtv-users/2012-April/331164.html,
a kernel crash is triggered when trying to run mythtv with a HVR950Q tuner.
The crash condition is due to res_free() being called to free something that
has is not reserved. The actual reason for this mismatch of reserve/free is
not known; however, using a BUG_ON rather than a WARN_ON seems unfortunate.

Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
---
drivers/media/video/au0828/au0828-video.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/media/video/au0828/au0828-video.c b/drivers/media/video/au0828/au0828-video.c
index 0b3e481..5c53e38 100644
--- a/drivers/media/video/au0828/au0828-video.c
+++ b/drivers/media/video/au0828/au0828-video.c
@@ -891,8 +891,13 @@ static int res_locked(struct au0828_dev *dev, unsigned int bit)
static void res_free(struct au0828_fh *fh, unsigned int bits)
{
struct au0828_dev *dev = fh->dev;
+ unsigned int bits2 = fh->resources & bits;

- BUG_ON((fh->resources & bits) != bits);
+ if (bits2 != bits) {
+ WARN_ONCE(true, "au0828: Trying to free resource 0x%x"
+ " without reserving it\n", bits);
+ return;
+ }

mutex_lock(&dev->lock);
fh->resources &= ~bits;
--
1.7.10

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