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From:   Tomasz Figa <tfiga@chromium.org>
Date:   Wed, 24 Jan 2018 18:51:39 +0900
Message-ID: <CAAFQd5AjisfRTefYthLgecRYroi4gVunEwX2DzhD0ywMOO5Yzg@mail.gmail.com>
Subject: Re: [PATCH v4 08/13] iommu/rockchip: Control clocks needed to access
 the IOMMU
To:     JeffyChen <jeffy.chen@rock-chips.com>
Cc:     Randy Li <randy.li@rock-chips.com>,
        Robin Murphy <robin.murphy@arm.com>,
        linux-kernel@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
        devicetree@vger.kernel.org, simon xue <xxm@rock-chips.com>,
        Joerg Roedel <joro@8bytes.org>,
        Ricky Liang <jcliang@chromium.org>,
        "open list:ARM/Rockchip SoC..." <linux-rockchip@lists.infradead.org>,
        "list@263.net:IOMMU DRIVERS <iommu@lists.linux-foundation.org>, Joerg
        Roedel <joro@8bytes.org>," <iommu@lists.linux-foundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        "list@263.net:IOMMU DRIVERS <iommu@lists.linux-foundation.org>, Joerg
        Roedel <joro@8bytes.org>," <linux-arm-kernel@lists.infradead.org>,
        Heiko Stuebner <heiko@sntech.de>
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On Mon, Jan 22, 2018 at 1:09 PM, JeffyChen <jeffy.chen@rock-chips.com> wrote:
> Hi Randy,
>
>
> On 01/22/2018 10:15 AM, JeffyChen wrote:
>>
>> Hi Randy,
>>
>> On 01/22/2018 09:18 AM, Randy Li wrote:
>>>>
>>>>
>>> Also the power domain driver could manage the clocks as well, I would
>>> suggest to use pm_runtime_*.
>>
>>
>> actually the clocks required by pm domain may not be the same as what we
>> want to control here, there might be some clocks only be needed when
>> accessing mmu registers.
>>
>> but i'm not very sure about that, will confirm it with Simon Xue.
>
>
> confirmed with Simon, there might be some iommus don't have a pd, and the
> CONFIG_PM could be disabled.
>
> so it might be better to control clocks in iommu driver itself.
>

Agreed with Jeffy.

I'd give Reviewed-by, but this is my own patch reposted by Jeffy
(thanks!), so it wouldn't have any value. :)

Best regards,
Tomasz