Messages in this thread | | | Date | Tue, 9 Jan 2018 00:45:30 +0300 | From | Mikhail Zaytsev <> | Subject | Re: [PATCH v2 1/2] USB: serial: ark3116: Remove unused TIOCSSERIAL ioctl case. |
| |
On Mon, 8 Jan 2018 16:28:58 +0100 Johan Hovold <johan@kernel.org> wrote:
> On Mon, Jan 08, 2018 at 11:33:32AM +0100, Oliver Neukum wrote: > > Am Samstag, den 06.01.2018, 20:14 +0300 schrieb Mikhail Zaytsev: > > > The patch removes unused TIOCSSERIAL ioctl case and adds the default block > > > to the switch. This will make the ioctl return -ENOTTY to user space (e.g. > > > setserial), because TIOCSSERIAL really isn't supported for these devices > > > currently. > > > > Hi, > > > > this will break software that is now running on these devices, > > won't it? Do you know why those devices basically ignore the > > ioctl? > > Yeah, that was my initial reactions as well, but then again, any sane > user space cannot rely on these ioctl being implemented for all tty > devices. > > I did some digging now and these (dummy) ioctl implementations where > added by commit 2f430b4bbae7 ("USB: ark3116: Add TIOCGSERIAL and > TIOCSSERIAL ioctl calls.") back in 2006. This in turn appears to have > been triggered by a change in a user space tool, wvdial, which started > erroring out if either was missing. > > I found a couple of bug reports about that through google, and looking > at the wvstreams (library) code now, it looks like the issue has indeed > been resolved by handling errors more gracefully (e.g. just logging > them). > > So I'm willing to give this a try, and if anyone complains later we add > back (or implement) TIOCSSERIAL. >
Thanks Johan. I looked the commit 2f430b4bbae7. Author just did a cut'n'paste from other USB serial drivers. I think that it would be better remove the TIOCGSERIAL implementation too.
Mikhail
| |