[PATCH v6 15/15] ARM: dts: rename the clock of MIPI DSI 'pll_clk' to 'sclk_mipi'

Krzysztof Kozlowski k.kozlowski at samsung.com
Mon Jun 22 05:20:57 PDT 2015


2015-06-22 21:10 GMT+09:00 Inki Dae <inki.dae at samsung.com>:
> On 2015년 06월 22일 20:59, Krzysztof Kozlowski wrote:
>> 2015-06-22 20:42 GMT+09:00 Inki Dae <inki.dae at samsung.com>:
>>> + Krzysztof
>>>
>>> On 2015년 06월 22일 18:10, Inki Dae wrote:
>>>> On 2015년 06월 12일 21:59, Hyungwon Hwang wrote:
>>>>> The clock which was named as 'pll_clk' is actually not the clock source
>>>>> of PLL in MIPI DSI. This patch fixes this disagreement.
>>>>
>>>> Mr. Kukjin and Krzysztof, can you give me Acked-by or Singed-off-by? I'd
>>>> like to merge this patch to mainline through drm-next.
>>
>> Dear Hyungwon Hwang,
>>
>> Please always CC samsung-soc mailing list on such patches. I won't
>> receive it on my personal email if you don't CC the list. The
>> get_maintainers.pl gives necessary addresses.
>>
>> Comment below,
>>
>>>>
>>>> Thanks,
>>>> Inki Dae
>>>>
>>>>>
>>>>> Signed-off-by: Hyungwon Hwang <human.hwang at samsung.com>
>>>>> ---
>>>>> Changes before:
>>>>> - Refer https://patchwork.kernel.org/patch/6191811
>>>>> Changes for v6:
>>>>> - None
>>>>>
>>>>>  arch/arm/boot/dts/exynos4.dtsi | 2 +-
>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/arch/arm/boot/dts/exynos4.dtsi b/arch/arm/boot/dts/exynos4.dtsi
>>>>> index e20cdc2..1538d7a 100644
>>>>> --- a/arch/arm/boot/dts/exynos4.dtsi
>>>>> +++ b/arch/arm/boot/dts/exynos4.dtsi
>>>>> @@ -167,7 +167,7 @@
>>>>>              phys = <&mipi_phy 1>;
>>>>>              phy-names = "dsim";
>>>>>              clocks = <&clock CLK_DSIM0>, <&clock CLK_SCLK_MIPI0>;
>>>>> -            clock-names = "bus_clk", "pll_clk";
>>>>> +            clock-names = "bus_clk", "sclk_mipi";
>>
>> It seems wrong. The driver fetches reference from a name of "pll_clk",
>> not "sclk_mipi". Also bindings documentation mentions pll_clk and
>> bus_clk only.
>
> Krzysztof,
>
> There is your missing point. The driver is already considered for
> pll_clk also. See the below codes,
>
> #define OLD_SCLK_MIPI_CLK_NAME "pll_clk"
> ...
>
>         for (i = 0; i < dsi->driver_data->num_clks; i++) {
>                 dsi->clks[i] = devm_clk_get(dev, clk_names[i]);
>                 if (IS_ERR(dsi->clks[i])) {
>                         if (strcmp(clk_names[i], "sclk_mipi") == 0) {
>                                 strcpy(clk_names[i], OLD_SCLK_MIPI_CLK_NAME);
>                                 i--;
>                                 continue;
>                         }
>
>                         dev_info(dev, "failed to get the clock: %s\n",
>                                         clk_names[i]);
>                         return PTR_ERR(dsi->clks[i]);
>                 }
>         }
>
> Above codes make the driver to try to get the pll_clk - defined as
> OLD_SCLK_MIPI_CLK_NAME macro - again if getting sclk_mipi clock failed
> so there is no problem even though a little bit ugly.
>
> As you know, we should guarantee the backward compatibility so this
> codes check two clock names.

I am looking at next-20150622 and file
drivers/gpu/drm/exynos/exynos_drm_dsi.c. There is no such code there.
There is only pll_clk. No sclk_mipi.

Maybe it was changed by other patch... but I haven't received it. Also
I cannot find such patch on linux-kernel, linux-arm-kernel and
linux-samsung-soc. I cannot ack something that I cannot see :) .

If you sent whole patchset to my office address, then I will look at
it tomorrow. From home I can only look at LKML patches.

Best regards,
Krzysztof


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