On Mon, Nov 20, 2017 at 7:54 AM, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote:
> Some system control registers need hardware spinlock to synchronize
> between the multiple subsystems, so we should add hardware spinlock
> support for syscon.
>
> @@ -87,6 +88,12 @@ static struct syscon *of_syscon_register(struct device_node *np)
> if (ret)
> reg_io_width = 4;
>
> + ret = of_hwspin_lock_get_id(np, 0);
> + if (ret > 0) {
> + syscon_config.hwlock_id = ret;
> + syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
> + }
Hi Baolin,
The error handling here seems insufficient, I think we have to treat
the following cases separately:
- ret>0 (this is fine)
- no spinlock in DT: of_hwspin_lock_get_id currently returns -EINVAL,
we probably want to use a different return code (maybe -ESRCH ?)
here so we can tell the difference beween no spinlock, and an
invalid spinlock
- deferred probing: if the spinlock is there but the driver is not
yet available, we may need to propagate the -EPROBE_DEFER
here
- other error: this would probably be a fatal condition here, and
we should print a warning and clean up.
Arnd
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