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. thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
