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Subject: Re: [PATCH v2] ARM: tegra: enforce PM requirement
To:     Dmitry Osipenko <digetx@gmail.com>,
        Russell King - ARM Linux admin <linux@armlinux.org.uk>
CC:     <jhogan@kernel.org>, <thierry.reding@gmail.com>,
        <jonathanh@nvidia.com>, <linux-kernel@vger.kernel.org>
References: <1551169537-17548-1-git-send-email-spujar@nvidia.com>
 <20190226091308.ycruijz2lcziv5gt@shell.armlinux.org.uk>
 <562c4307-74ad-fd9d-74e7-36ac19315d0b@gmail.com>
From:   Sameer Pujar <spujar@nvidia.com>
Message-ID: <92ca8288-3b57-0683-83fa-445e2be42086@nvidia.com>
Date:   Wed, 27 Feb 2019 11:47:00 +0530
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On 2/26/2019 10:22 PM, Dmitry Osipenko wrote:
> 26.02.2019 12:13, Russell King - ARM Linux admin =D0=BF=D0=B8=D1=88=D0=B5=
=D1=82:
>> On Tue, Feb 26, 2019 at 01:55:37PM +0530, Sameer Pujar wrote:
>>> The requirement for this came while adding runtime PM support for HDA
>>> driver. There were concerns about driver explicitly handling !PM case.
>>> In general, drivers need to handle !PM case with work arounds for
>>> managing clocks and power explicitly, which is not really necessary
>>> when PM support on tegra is in good shape. In fact ARM 64-bit Tegra
>>> platforms enforce PM support and there is no reason why this cannot be
>>> done for 32-bit.
>>>
>>> More details with regards to above can be found in following patch,
>>> http://patchwork.ozlabs.org/patch/1036645/
>>>
>>> This patch selects PM unconditionally and drivers can rely on runtime
>>> PM framework for clock and power management.
>> What if the drivers are re-used on another SoC IP?  Doesn't this lead
>> to unexpected failures?
>>
>> If you want to do this, maybe also make those drivers depend on PM as
>> well?
> The commit message is inaccurate, it is intended for the Tegra HDA driver=
 and not for some generic driver. The overall final intent is to remove dep=
endency on the PM availability for all of Tegra drivers to "make Tegra main=
tainers life easier".
Wanted to convey that finally it would be the case for all Tegra=20
drivers. I will update commit message to make it more clear.