Hi Nicolas, On 09/05/2014 05:15 AM, Nicolas Ferre wrote: > On 03/09/2014 18:09, Richard Genoud : > Richard, > > Indeed it seems needed: > > Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx> > > > But BTW, I see just below a call to the atmel_enable_ms() function in > atmel_set_ldisc(). My question is, shouldn't we also add this > atmel_disable_ms() in the alternative that disables the PPS in this > ldisc function? I have that change in another series but it has to wait for: 1. another series that fixes races setting and clearing the controlling tty (and reduces the footprint of tty_mutex) 2. a series built on that which moves tty_lock() out from under tty_mutex when reopening ttys This allows the tty_lock to be held while closing the tty. 3. a series which removes the ldisc flush from the serial core, among some other locking fixes in the serial core. This fixes a lock inversion between the termios_rwsem and the port mutex. All of which enables the set_ldisc() notification to be safely passed termios so it can use UART_ENABLE_MS() and also claim the port mutex to change the UPF_HARDPPS_CD flag, which is currently non-atomic and may corrupt the uart port flags field. The series also claims the port lock around the *_enable_ms() in the various set_ldisc() handlers to protect the hardware re-programming :) Right now, all of this is temporarily stuck on the most recent patch series, which hinges on whether the kernel should continue to support non-atomic byte stores. Regards, Peter Hurley -- 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
