On Tuesday 2 May 2017, at 10:34, Johan Hovold wrote: > On Fri, Apr 28, 2017 at 11:27:20AM +0200, Anthony Mallet wrote: > > This is due to commit 557aaa7 > > https://github.com/torvalds/linux/commit/557aaa7ffab639d0190b935a041b16ae44606342 > > that silently/partially ignores the ASYNC_LOW_LATENCY flag in > > set_serial_info(), without returning EPERM, although > > ASYNC_LOW_LATENCY is explicitly listed in ASYNC_USR_MASK. > > Actually that commit did enable non-privileged users to set the flag, but > it would not take effect until next open. A later commit then broke this > behaviour, but no one has noticed for about seven years. OK. Thanks for reviewing this. (Not taking effect until next open was a bit bad too, I think). > Yes, this looks like the right fix. > > Are you going to submit this as a proper patch that we can apply? Sure (I was just AFK for the week-end). Is it OK like this ? --- drivers/usb/serial/ftdi_sio.c~ 2017-04-28 11:20:30.339227000 +0200 +++ drivers/usb/serial/ftdi_sio.c 2017-04-28 11:20:52.647773000 +0200 @@ -1505,9 +1505,9 @@ static int set_serial_info(struct tty_st (new_serial.flags & ASYNC_FLAGS)); priv->custom_divisor = new_serial.custom_divisor; +check_and_exit: write_latency_timer(port); -check_and_exit: if ((old_priv.flags & ASYNC_SPD_MASK) != (priv->flags & ASYNC_SPD_MASK)) { if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI) -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
