[PATCH v2 16/16] misc: support for I-8024 in LP-8x4x

Arnd Bergmann
2013-12-14T20:59:39Z

On Friday 13 December 2013, Sergei Ianovich wrote:
> +void nsleep(unsigned long nanosec)
> +{
> + ktime_t t = ns_to_ktime(nanosec);
> + long state = current->state;
> +
> + __set_current_state(TASK_UNINTERRUPTIBLE);
> + schedule_hrtimeout(&t, HRTIMER_MODE_REL);
> + __set_current_state(state);
> +}
> +
> +static void lp8x4x_slot_reset_AO(struct lp8x4x_slot *s)
> +{
> + int i;
> + mutex_lock(&s->lock);
> + for (i = 0; i < s->AO_len; i++)
> + s->AO[i] = 0x2000;
> + iowrite8(0x00, s->data_addr);
> + nsleep(450);
> + iowrite8(0xff, s->data_addr);
> + mutex_unlock(&s->lock);
> +}

Have you checked that the nsleep definition actually does the
right thing here? 450 nanoseconds must be close the latency
you get from calling schedule_hrtimeout(). I'd suggest using
either ndelay() or usleep_range() instead, depending on your
needs.

If nsleep is really useful here, we should probably add that
as a generic API rather than having it in one driver.

Arnd