From mgross@linux.intel.com Tue Sep 25 11:13:23 2007 From: Mark Gross Date: Mon, 24 Sep 2007 09:28:14 -0700 Subject: USB: usb-skeleton leaking locks on open To: Greg KH Message-ID: <20070924162814.GB5227@linux.intel.com> Content-Disposition: inline This weekend I was hacking around with a trivial USB driver for talking to the boot load firmware of a USB Bit Whacker. It's running the MicroChip Pic18 boot loader firmware and I'm putting together a flash program for writing new FW to the thing. Anyway in my use of the usb-skeleton.c as my starting point I discovered my test program was getting hung up after attempting to write a buffer. The application and driver where hung in a way that required me to reboot to get it to clean up so I could try again. It turned out the code path through skel_open can grap the driver's io_mutex lock and forget to release it. The following patch fixes the problem for me. Signed-off-by: Mark Gross Cc: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- drivers/usb/usb-skeleton.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/usb/usb-skeleton.c +++ b/drivers/usb/usb-skeleton.c @@ -125,6 +125,7 @@ static int skel_open(struct inode *inode /* save our object in the file's private structure */ file->private_data = dev; + mutex_unlock(&dev->io_mutex); exit: return retval;