Re: [PATCH v2 08/11] gpiolib: emit a debug message when adding events to a full kfifo

From: Andy Shevchenko
Date: Wed Dec 04 2019 - 17:28:21 EST


On Wed, Dec 4, 2019 at 6:04 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
>
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>
> Currently if the line-event kfifo is full, we just silently drop any new
> events. Add a ratelimited debug message so that we at least have some
> trace in the kernel log of event overflow.
>

Hmm... I don't like prints in IRQ context (even threaded).
Can we rather switch to trace points at some point?

> @@ -975,6 +975,9 @@ static irqreturn_t lineevent_irq_thread(int irq, void *p)
> ret = kfifo_in_spinlocked(&le->events, &ge, 1, &le->wait.lock);
> if (ret)
> wake_up_poll(&le->wait, EPOLLIN);
> + else
> + pr_debug_ratelimited(
> + "%s: event FIFO is full - event dropped\n", __func__);
>
> return IRQ_HANDLED;

--
With Best Regards,
Andy Shevchenko