2017-11-30 02:04:43

by Baolin Wang

[permalink] [raw]
Subject: Re: [PATCH v3] mfd: syscon: Add hardware spinlock support

Hi Arnd,

On 29 November 2017 at 18:07, Arnd Bergmann <[email protected]> wrote:
> On Mon, Nov 20, 2017 at 7:54 AM, Baolin Wang <[email protected]> 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.

You are correct and I will add some error handling. Thanks for your comments.

--
Baolin.wang
Best Regards

From 1585404966762263701@xxx Wed Nov 29 12:53:17 +0000 2017
X-GM-THRID: 1584567099391769753
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread