Messages in this thread | | | Subject | Re: [PATCH 01/26] tty: mxser: drop low-latency workaround | From | Jiri Slaby <> | Date | Thu, 22 Apr 2021 07:59:30 +0200 |
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On 21. 04. 21, 11:54, Johan Hovold wrote: > Commit 67d2bc58afdd ("Char: mxser_new, fix recursive locking") worked > around the infamous low_latency behaviour of tty_flip_buffer_push() by > simply dropping and reacquiring the port lock in the interrupt handler. > > Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), > tty_flip_buffer_push() always schedules a work item to push data to the > line discipline and there's no need to keep any low_latency hacks around. > > Link: https://lore.kernel.org/lkml/3018694794025219@wsc.cz/T/#m06b04c640a7b6f41afb3d34a4cf29b1df4935d3a > Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
> --- > drivers/tty/mxser.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c > index 2d8e76263a25..16a852ecbe8a 100644 > --- a/drivers/tty/mxser.c > +++ b/drivers/tty/mxser.c > @@ -2155,14 +2155,7 @@ static void mxser_receive_chars(struct tty_struct *tty, > port->mon_data.rxcnt += cnt; > port->mon_data.up_rxcnt += cnt; > > - /* > - * We are called from an interrupt context with &port->slock > - * being held. Drop it temporarily in order to prevent > - * recursive locking. > - */ > - spin_unlock(&port->slock); > tty_flip_buffer_push(&port->port); > - spin_lock(&port->slock); > } > > static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port) >
thanks, -- js
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