On Wed, Feb 8, 2017 at 10:59 PM, Samuel Thibault <samuel.thibault@xxxxxxxxxxxx> wrote: > Okash Khawaja, on Wed 08 Feb 2017 22:46:32 +0000, wrote: >> enable acess to tty device from kernel module > > You need much more explanations, and also this is based on a patch from > Alan Cox > (http://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1215095.html), > so you should integrate the explanations, something like: > > “ > tty_port: allow a port to be opened with a tty that has no file handle > > Let us create tty objects entirely in kernel space. > > With this a kernel created non file backed tty object could be used to handle > data, and set terminal modes. Not all ldiscs can cope with this as N_TTY in > particular has to work back to the fs/tty layer. > > The tty_port code is however otherwise clean of file handles as far as I can > tell as is the low level tty port write path used by the ldisc, the > configuration low level interfaces and most of the ldiscs. > > Currently you don't have any exposure to see tty hangups because those are > built around the file layer. However a) it's a fixed port so you probably > don't care about that b) if you do we can add a callback and c) you almost > certainly don't want the userspace tear down/rebuild behaviour anyway. > > This should however be sufficient if we wanted for example to enumerate all > the bluetooth bound fixed ports via ACPI and make them directly available. > > It doesn't deal with the case of a user opening a port that's also kernel > opened and that would need some locking out (so it returned EBUSY if bound > to a kernel device of some kind). That needs resolving along with how you > "up" or "down" your new bluetooth device, or enumerate it while providing > the existing tty API to avoid regressions (and to debug). > ” > > You'll need to have Alan Cox in Cc when actually submitting the patch, > so he gets to comment on it. You'll then have to add your Signed-off-By > along his own, see linux/Documentation/SubmittingPatches for the > details. > > Samuel Okay, wasn't best placed to put in details for this this one so the above really helps. Will follow this with better formatted patch set. _______________________________________________ Speakup mailing list Speakup@xxxxxxxxxxxxxxxxx http://linux-speakup.org/cgi-bin/mailman/listinfo/speakup
