Messages in this thread | | | From | Arnd Bergmann <> | Date | Wed, 29 Nov 2017 11:07:23 +0100 | Subject | Re: [PATCH v3] mfd: syscon: Add hardware spinlock support |
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On Mon, Nov 20, 2017 at 7:54 AM, Baolin Wang <baolin.wang@linaro.org> 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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