Dale Farnsworth wrote: > > We need to release the port lock when we call tty_flip_buffer_push() > to avoid a deadlock when the serial-core routines try to acquire > the same lock. This deadlock has been observed on CONFIG_PREEMPT_RT > configurations. > > Signed-off-by: Dale Farnsworth <dale@xxxxxxxxxxxxxx> > Cc: <mgreer@xxxxxxxxxx> > --- > drivers/serial/mpsc.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/drivers/serial/mpsc.c b/drivers/serial/mpsc.c > index c9f53e7..158d748 100644 > --- a/drivers/serial/mpsc.c > +++ b/drivers/serial/mpsc.c > @@ -1065,7 +1065,9 @@ next_frame: > if ((readl(pi->sdma_base + SDMA_SDCM) & SDMA_SDCM_ERD) == 0) > mpsc_start_rx(pi); > > + spin_unlock(&pi->port.lock); > tty_flip_buffer_push(tty); > + spin_lock(&pi->port.lock); > return rc; > } Acked-by: Mark A. Greer <mgreer@xxxxxxxxxx> -- 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
