On Thu, Mar 20, 2014 at 9:36 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Thu, Mar 20, 2014 at 08:37:29PM -0500, Felipe Balbi wrote: >> On Thu, Mar 20, 2014 at 08:35:57PM -0500, Felipe Balbi wrote: >> > Hi, >> > >> > On Thu, Mar 20, 2014 at 05:12:28PM -0700, Greg KH wrote: >> > > On Thu, Mar 20, 2014 at 06:52:10PM -0500, Felipe Balbi wrote: >> > > > Hi folks, >> > > > >> > > > I've been toying with the idea of removing >> > > > drivers/tty/serial/omap-serial.c since that's, to put it bluntly, an >> > > > ungly copy of 8250 driver. >> > > > >> > > > The original concern was wrt suspend/resume but I think it'd be a far >> > > > better approach to implement runtime PM in 8250 and write a rather small >> > > > 8250-omap.c glue (much like 8250-acorn.c or 8250-dw.c) just to get the >> > > > OMAP-specific details out of the way. >> > > > >> > > > The question I have is: omap-serial.c calls the serial devnodes ttyO\d, >> > > > instead of ttyS\d so removing omap-serial.c would have a direct impact >> > > > in userland. I wonder if it's an acceptable "regression" considering >> > > > we'd be able to reuse 8250 gaining proper Flow Control support, proper >> > > > DMA support, years and years of bug-fixes, etc. >> > > >> > > Breaking device node names is a contentious issue for serial ports, I >> > > don't think you can do that :( >> > >> > would an upstream udev rule creating a symbolic link from ttyO to ttyS >> > be enough ? >> > >> > I didn't test this yet but I guess this is enough (?) >> > >> > KERNEL=="ttyO[0-9]", GROUP="dialout", SYMLINK+="ttyS" >> >> or actually it should be to other way around, ttyS would be the real >> device: >> >> KERNEL=="ttyS[0-9]", GROUP="dialout", SYMLINK+="ttyO" > > As udev rules don't ship with the kernel, this might be tough to do :( > > Might be easier to make the 8250 driver handle different "names" like > Alan said. On the support side, I'm not looking forward to this for beagle/panda users. We've already converted them once from ttySx -> ttyOx back in 2.6.33/2.6.34? days. That was an irc/email/u-boot/kernel nightmare... Regards, -- Robert Nelson http://www.rcn-ee.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
