Messages in this thread | | | From | Jim Cromie <> | Date | Fri, 20 May 2011 23:15:04 -0600 | Subject | Re: [PATCH 00/23] add register_chrdev_ids() to char_dev.c, API |
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On Thu, May 19, 2011 at 4:44 PM, Greg KH <gregkh@suse.de> wrote: > On Thu, May 19, 2011 at 03:33:03PM -0600, Jim Cromie wrote: >> over on kernelnewbies, gregkh said: >> >> The chardev stuff is a mess, I keep meaning for years to clean it >> up. Any proposals on a sane interface for this stuff is greatly >> appreciated. >> >> this is a 1st step. >> >> register_chrdev_ids() replaces and deprecates register_chrdev_region() >> and alloc_chrdev_region() with a single function that works for both >> dynamic and static major numbers. >> >> Like alloc_chrdev_region(), 1st arg is a dev_t*, but its an in/out >> parameter, and expects both major and minor to be preset, and thus the >> separate minor arg is dropped. If major == 0, a dynamic major is >> reserved, saved into 1st arg, and thus available to caller afterwards. >> >> [PATCH 01/23] add register_chrdev_ids() to char_dev.c, API >> [PATCH 02/23] reimplement alloc_chrdev_region with >> [PATCH 03/23] use register_chrdev_ids to replace >> [PATCH 04/23] use register_chrdev_ids in drivers/tty/ >> [PATCH 05/23] use register_chrdev_ids in drivers/infiniband/ >> [PATCH 06/23] use register_chrdev_ids in drivers/media/ >> [PATCH 07/23] use register_chrdev_ids in drivers/s390/ >> [PATCH 08/23] use register_chrdev_ids in drivers/scsi/ >> [PATCH 09/23] use register_chrdev_ids in drivers/staging/ >> >> Ive held back the rest, no point in spamming. > > It's a nice first step, but that's the easy part, what is your 2nd > through 4th one going to be? :) > > I'd also like to sanatize the function namespace a bit as well, how > about chrdev_register_ids() instead?
that seems sensible, modern. also have register_chrdev(), which I presume should also be fixed.
> Ideally, we could drop down to a single register/unregister pair of > functions, that are easy to use and understand.
__register_chrdev() does more stuff, mainly around cdevs, fops. If fops was passed as NULL, we just do the __register_chardev_region() and return early, skipping the cdev_alloc() and everything afterwards, thus yielding register_chrdev_ids() behavior.
> Do you think you can > get there with this intermediate step or do you want to step back and > rethink this?
hmm. If above is right, theres no need for the new api fn I added, and probably should also drop the __ on both (un)?register_chardev. So thats step 2 :) Any ideas for 3 ?
btw, I think theres a major/minor error in the linuxdoc for the count param in some of these register-* functions. I'll take a closer look, and send a patch RSN if needed, even if fn is going away later.
> thanks, > > greg k-h > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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