Dear Dan, Thanks for reviewing this patch. On Wed, Mar 08, 2017 at 08:54:47AM +0300, Dan Carpenter wrote: > On Sun, Mar 05, 2017 at 03:22:33AM +0800, Cheah Kok Cheong wrote: > > If comedi module is loaded with the following max allowed parameter > > [comedi_num_legacy_minors=48], subsequent loading of an auto-configured > > device will fail. > > Don't set comedi_num_legacy_minors=48, then? > > This doesn't seem like the right fix at all. Why only allow one auto > configured board? Why not 5 or 10? >
Let me explain, the original intended behaviour is to allow user to reserve up to 48 minor numbers for legacy devices. Therefore [sudo modprobe comedi comedi_num_legacy_minors=3] will allocate minor number 0, 1, 2 for legacy devices. Subsequent loading of an auto-configured device will use minor number 3. And the next one number 4 so on and so forth. Now for the corner case of [comedi_num_legacy_minors=48] which is supposed to reserve minor number 0 till 47 for legacy devices, and is supposed to allocate number 48 and so on for auto-configured devices, does not allocate number 48 anymore after commit 38b9722a4414. This is due to the changes in comedi_alloc_board_minor(). As to why I chose to limit [comedi_num_legacy_minors=47], is given in the commit log. This will allow user to allocate 0 till 46 for legacy devices and subsequent auto-configured devices will start from 47 and so forth. I don't think anybody will miss one less number for legacy devices otherwise there'll be complains earlier on. Thanks. Brgds, CheahKC > regards, > dan carpenter > _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
