linux-kernel - Re: [PATCH V3 1/2] spmi: remove wakeup command before slave probe

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Date:	Wed, 18 Feb 2015 11:17:13 -0800
From:	Stephen Boyd <sboyd@...eaurora.org>
To:	Josh Cartwright <joshc@....teric.us>,
	Gilad Avidov <gavidov@...eaurora.org>
CC:	sdharia@...eaurora.org, mlocke@...eaurora.org,
	linux-arm-msm@...r.kernel.org, gregkh@...uxfoundation.org,
	linux-kernel@...r.kernel.org, iivanov@...sol.com,
	galak@...eaurora.org, agross@...eaurora.org
Subject: Re: [PATCH V3 1/2] spmi: remove wakeup command before slave probe

On 02/18/15 07:39, Josh Cartwright wrote:
> On Mon, Feb 09, 2015 at 03:51:11PM -0700, Gilad Avidov wrote:
>> According to spmi spec a slave powers up into startup state and then
>> transitions into active state. Thus, the wakeup command is not required
>> before calling the slave's probe. The wakeup command is only needed for
>> slaves that are in sleep state after receiving the sleep command.
>>
>> This is a bug since spmi master controllers, such as spmi-pmic-arb,
>> which have no support for wakeup command return an error on that
>> command and thus fail before reaching a slave driver probe.
> If masters are required by the spec to support all commands as Stephen
> mentions, then I'd argue this is not a bug in the core code at all, but
> in the spmi-pmic-arb driver.  But, unfortunately, having lost access to
> the spec, I'll defer.
>
> Regardless, I think this is useful as an optimization, just with dubious
> justification.
>
> Therefore,
>
> Acked-by: Josh Cartwright <joshc@....teric.us>
>
>

Agreed, it's mostly an optimization and aligns the code more with the
spec. How about we drop the "This is a bug" part?

With that done,

Reviewed-by: Stephen Boyd <sboyd@...eaurora.org>

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

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