On 2013-06-11 01:58, H Hartley Sweeten wrote:
Introduce a new subdevice flag, SDF_FREE_SPRIV, to allow the comedi core to automatically free the subdevice private data during the cleanup_device() stage of the detach.
This is an implementation detail that should really be hidden from userspace. With this patch it is exposed through the 'subd_flags' member of 'struct comedi_subdinfo'. That can easily be fixed by masking out the 'SDF_FREE_SPRIV' flag when setting 'us->subd_flags' in 'do_subdinfo_ioctl()'. Ideally, 'SDF_FREE_SPRIV' shouldn't appear in "comedi.h" at all as should be of no interest to userspace.
As we're running out of SDF_ values, we might want to reassign the current 'SDF_FREE_SPRIV' value to some other user-visible meaning at a later date.
We could put the internal flags in a different member of 'struct comedi_subdevice'; either define a new member or abuse the existing 'runflags' member. (A new member could be placed in a 32-bit hole in the structure for 64-bit kernels, so would only use extra space for 32-bit kernels.) (There are various members of 'struct comedi_subdevice' that could be stripped out to save space if necessary, such as 'settling_time_0', 'flags' and 'flaglist'. These were intended to pass various details from drivers to userspace but none of the existing drivers actually set them.)
-- -=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=- -=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=- _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
