Re: [PATCH v11 10/27] iommu/exynos: use managed device helper functions

From: Sachin Kamat
Date: Wed Mar 19 2014 - 05:01:27 EST


On 19 March 2014 14:29, Cho KyongHo <pullip.cho@xxxxxxxxxxx> wrote:
> On Tue, 18 Mar 2014 16:14:53 +0100, Tomasz Figa wrote:
>> On 18.03.2014 12:09, Cho KyongHo wrote:
>> > On Fri, 14 Mar 2014 20:52:43 +0530, Sachin Kamat wrote:
>> >> Hi KyongHo,
>> >>
>> >> On 14 March 2014 10:35, Cho KyongHo <pullip.cho@xxxxxxxxxxx> wrote:
>> >>> This patch uses managed device helper functions in the probe().
>> >>>
>> >>> Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
>> >>> ---
>> >> [snip]
>> >>
>> >>> + data->clk = devm_clk_get(dev, "sysmmu");
>> >>> + if (IS_ERR(data->clk)) {
>> >>> + dev_info(dev, "No gate clock found!\n");
>> >>> + data->clk = NULL;
>> >>> + }
>> >>
>> >> Why aren't you returning from here upon error?
>> >
>> > It is for the case of a System MMU which does not need clock gating.
>> >
>>
>> Are there really such cases?
>>
>
> Yes.
> Especially in the case of initial stage of new SoC development.
>
> I have experianced some software workaround for H/W restriction
> needs prevention of clock gating for some devices.

So aren't these basically some exceptions/hacks rather than the usual way
of functioning of the device?

--
With warm regards,
Sachin
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