Re: [PATCH 0/4] Fix problems with Exynos4412 ISP clocks

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hi Krzysztof,

On 2017-10-02 19:36, Krzysztof Kozlowski wrote:
> On Mon, Oct 02, 2017 at 12:47:55PM +0200, Marek Szyprowski wrote:
>> Exynos4412 ISP clock controller is located in the SOC area, which belongs
>> to ISP power domain. This was not properly handled by the current
>> Exynos4-clk driver. This patchset instantiates a separate clock driver
>> for those clocks, updates all clients of ISP clocks and ensures that
>> the driver is properly integrated in ISP power domin using runtime PM
>> feature of the clock framework.
>>
>> This finally solves all the mysterious freezes in accessing ISP clocks
>> when ISP power domain is disabled.
>>
>> The last patch breaks support for old dtbs. It can be applied when all
>> boards are updated. Exynos4412 ISP subsystem is only used by Trats2
>> boards, for which kernel is updated always together with the dtb file,
>> so the last patch can be applied to the next kernel release after merging
>> the DTS patch.
> I am fine with this approach. However I see that third patch (dts)
> depends on previous so it will also wait one cycle. arm-soc folks for
> some time do not accept code mixed with dts.
>
> Unless you can split dts into two patches: adding new clock controller
> and removing old. In such case the new clock could be applied in
> parallel to clk code changes.

DTS patch cannot be split into two patches without breaking ISP support,
because adding a new clock controller requires changes in the clients and
register resource size of the old one, so either old or new one has to be
fully defined. If arm-soc cannot pull mixed branches, then I'm okay with
postponing DTS changes by one release.

 > ...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland