staging: comedi: simplify driver module counting
For a legacy device attachment with the `COMEDI_DEVCONFIG` ioctl, `do_devconfig_ioctl()` calls `comedi_device_attach()` to find a matching device driver and attach the device. It then tries to increment the device driver's module count and if that fails it detaches the device. So on successful attachment of a device by the `COMEDI_DEVCONFIG` ioctl, the device driver's module count will have been incremented. `comedi_device_attach()` is called from nowhere else. It already increments the device driver's module count temporarily and decrements it again; if it gets as far as calling `comedi_device_postconfig()` the module count is decremented within that function. Simplify the above by removing the decrement of the device driver module count from `comedi_device_postconfig()`. If the call to `comedi_device_postconfig()` succeeds, `comedi_device_attach()` will return with the module count still incremented, otherwise decrement the module count before returning the error. Don't try and increment the module count in `do_devconfig_ioctl()` after a successful return from `comedi_device_attach()` as the module count has now already been incremented. `comedi_device_postconfig()` is also called by `comedi_auto_config()` which currently has to increment the device driver's module count temporarily so that `comedi_device_postconfig()` can decrement it, but always returns with no overall change to the module count. Remove all the module count manipulations from `comedi_device_postconfig()`. There is no other reason for `comedi_auto_config()` to increment the device driver's module count temporarily, since it is only called (indirectly) from the device driver itself (usually via one of the wrappers `comedi_pci_auto_config()` or `comedi_usb_auto_config()`). Signed-off-by:Ian Abbott <abbotti@mev.co.uk> Reviewed-by:
H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
d9740a03
Please register or sign in to comment