Return-Path: Date: Thu, 18 Aug 2016 16:16:36 +0100 From: One Thousand Gnomes To: Marcel Holtmann Cc: Pavel Machek , Greg Kroah-Hartman , "H. Nikolaus Schaller" , Rob Herring , Jiri Slaby , Sebastian Reichel , Peter Hurley , NeilBrown , Arnd Bergmann , Linus Walleij , linux-bluetooth@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, herkne@gmx.de Subject: Re: [RFC PATCH 0/3] UART slave device bus Message-ID: <20160818161636.0ef634a7@lxorguk.ukuu.org.uk> In-Reply-To: References: <20160818011445.22726-1-robh@kernel.org> <118926C8-F4D0-41F5-B6A8-690E0312F3FB@goldelico.com> <28DDAF2B-2341-403B-80D8-DA0A63F51FF1@holtmann.org> <20160818105521.GB7031@kroah.com> <20160818111046.GE7427@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-ID: On Thu, 18 Aug 2016 13:47:44 +0200 Marcel Holtmann wrote: > Hi Pavel, > > >>> I am actually not convinced that GPS should be represented as > >>> /dev/ttyS0 or similar TTY. It think they deserve their own driver > >>> exposing them as simple character devices. That way we can have a > >>> proper DEVTYPE and userspace can find them correctly. We can also > >>> annotate them if needed for special settings. > >> > >> I would _love_ to see that happen, but what about the GPS line > >> discipline that we have today? How would that match up with a char > >> device driver? > > > > ./drivers/usb/serial/garmin_gps.c ? > > > > Hmm, some cleanups would be welcome there... plus it would be good to > > know what is its interface to userland... it is not easily apparent > > from the code. > > however that driver is not a line discipline. That is just an USB driver. But I agree if we create a GPS driver framework / subsystem, then this one should be converted into using it. You can't convert it - you can duplicate it or pipe the data into an additional driver, but converting it would break back compatibility for existing configurations and violate Linus no regressions rule. Alan