Re: [PATCH] pinctrl: qcom: use restart_notifier mechanism for ps_hold

From: Kumar Gala
Date: Thu Sep 18 2014 - 19:02:25 EST



On Sep 18, 2014, at 3:49 PM, Josh Cartwright <joshc@xxxxxxxxxxxxxx> wrote:

> On Thu, Sep 18, 2014 at 03:47:20PM -0700, Kumar Gala wrote:
>> On Sep 18, 2014, at 3:32 PM, Josh Cartwright <joshc@xxxxxxxxxxxxxx> wrote:
>>
>>> By converting to the restart_notifier mechanism for restart, we allow
>>> for other mechanisms, like the watchdog, to be used for restart in the
>>> case where PS_HOLD has failed to reset the chip.
>>>
>>> Choose priority 128, as according to documentation, this mechanism "is
>>> sufficient to restart the entire system?.
>>
>> Will we use a higher priority for watchdog? or how would we fail over to watchdog?
>
> The registered restart handlers are called in (descending) priority
> order. This driver registers as 128, but conceivably there could be
> some super-board-specific restart mechanism that can register itself as
> higher priority than this and it will be attempted first.
>
> If PS_HOLD doesn't work, the lower priority restart handlers will
> continue to be called, including the watchdog, which is registering with
> the lowest priority (0).

Cool, thanks.

- k
--
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

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