Hi Kaneko-san, Mizuguchi-san,
On Sun, May 17, 2015 at 5:50 PM, Yoshihiro Kaneko <ykaneko0929@xxxxxxxxx> wrote:
> From: Kazuya Mizuguchi <kazuya.mizuguchi.ks@xxxxxxxxxxx>
>
> This patch calls work_fn_rx() directly so that the driver can avoid
> executing of next sci_dma_rx_complete() before work_fn_rx() completes.
What happened when sci_dma_rx_complete() was executed again before
work_fn_rx() completed? Anything bad?
> Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@xxxxxxxxxxx>
> Signed-off-by: Yoshihiro Kaneko <ykaneko0929@xxxxxxxxx>
> ---
>
> This patch is based on the tty-next branch of Greg Kroah-Hartman's tty
> tree.
>
> v2 [Yoshihiro Kaneko]
> * Move work_fn_rx() up and remove a function prototype accorded
>
> drivers/tty/serial/sh-sci.c | 225 ++++++++++++++++++++++----------------------
> 1 file changed, 113 insertions(+), 112 deletions(-)
>
> diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> index e7d6566..5b216ea 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -1341,7 +1453,7 @@ static void sci_dma_rx_complete(void *arg)
> if (count)
> tty_flip_buffer_push(&port->state->port);
>
> - schedule_work(&s->work_rx);
> + work_fn_rx(&s->work_rx);
> }
There's still a call to schedule_work(&s->work_rx) in rx_timer_fn().
Which means that if work_fn_rx() in the DMA callback takes longer than the
expiration of the timer, work_fn_rx() may be re-entered through the workqueue.
Oops...
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
--
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
