On Mon, Jan 07, 2013 at 05:34:28PM -0600, H Hartley Sweeten wrote: > On Monday, January 07, 2013 4:23 PM, Greg Kroah-Hartman wrote: > > On Wed, Jan 02, 2013 at 04:21:23PM +0000, Ian Abbott wrote: > >> When a low-level comedi driver auto-configures a device, a `struct > >> comedi_dev_file_info` is allocated (as well as a `struct > >> comedi_device`) by `comedi_alloc_board_minor()`. A pointer to the > >> hardware `struct device` is stored as a cookie in the `struct > >> comedi_dev_file_info`. When the low-level comedi driver > >> auto-unconfigures the device, `comedi_auto_unconfig()` uses the cookie > >> to find the `struct comedi_dev_file_info` so it can detach the comedi > >> device from the driver, clean it up and free it. > >> > >> A problem arises if the user manually unconfigures and reconfigures the > >> comedi device using the `COMEDI_DEVCONFIG` ioctl so that is no longer > >> associated with the original hardware device. The problem is that the > >> cookie is not cleared, so that a call to `comedi_auto_unconfig()` from > >> the low-level driver will still find it, detach it, clean it up and free > >> it. > >> > >> Stop this problem occurring by always clearing the `hardware_device` > >> cookie in the `struct comedi_dev_file_info` whenever the > >> `COMEDI_DEVCONFIG` ioctl call is successful. > >> > >> Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx> > >> Cc: stable@xxxxxxxxxxxxxxx > >> --- > >> @Greg: This was originally sent on 4th December. It clashes with > >> Hartley's "[PATCH 04/26] staging: comedi: use comedi_dev_from_minor()" > >> of 19th December. It would be nice if my patch takes precedence so that > >> it can be used as-is in the stable kernels, though unfortunately that > >> would require a slight re-work of Hartley's patch. > > > > I've applied this, and Hartley's patches, and merged the branches > > together. I've fixed up the obvious build error, can both of you verify > > that I didn't do anything wrong? It should be in the staging-next > > branch now. > > Look good to me. Great, thanks for checking. greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
