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Subject: Re: [PATCH] MIPS: ralink: define stubs for clk_set_parent to fix
 compile testing
To:     Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Sergei Shtylyov <sergei.shtylyov@gmail.com>,
        John Crispin <john@phrozen.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     thierry.reding@gmail.com, linux-tegra@vger.kernel.org,
        balbi@kernel.org, linux-usb@vger.kernel.org,
        kernel test robot <lkp@intel.com>
References: <20210316175725.79981-1-krzysztof.kozlowski@canonical.com>
 <880d5e61-fec5-e7d6-7403-b1823c77b3c1@gmail.com>
 <856fbd45-67ae-fed2-97c4-b555993d5ae9@canonical.com>
From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <1cd074f0-3a58-d1bf-2a72-4fadd0d3b796@gmail.com>
Date:   Wed, 17 Mar 2021 22:37:45 +0300
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17.03.2021 12:56, Krzysztof Kozlowski пишет:
> On 17/03/2021 10:52, Sergei Shtylyov wrote:
>> Hello!
>>
>> On 16.03.2021 20:57, Krzysztof Kozlowski wrote:
>>
>>> The Ralink MIPS platform does not use Common Clock Framework and does
>>> not define certain clock operations leading to compile test failures:
>>>
>>>      /usr/bin/mips-linux-gnu-ld: drivers/usb/phy/phy-tegra-usb.o: in function `tegra_usb_phy_init':
>>>      phy-tegra-usb.c:(.text+0x1dd4): undefined reference to `clk_get_parent'
>>>
>>> Reported-by: kernel test robot <lkp@intel.com>
>>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
>>> ---
>>>   arch/mips/ralink/clk.c | 14 ++++++++++++++
>>>   1 file changed, 14 insertions(+)
>>>
>>> diff --git a/arch/mips/ralink/clk.c b/arch/mips/ralink/clk.c
>>> index 2f9d5acb38ea..8387177a47ef 100644
>>> --- a/arch/mips/ralink/clk.c
>>> +++ b/arch/mips/ralink/clk.c
>>> @@ -70,6 +70,20 @@ long clk_round_rate(struct clk *clk, unsigned long rate)
>>>   }
>>>   EXPORT_SYMBOL_GPL(clk_round_rate);
>>>   
>>> +int clk_set_parent(struct clk *clk, struct clk *parent)
>>> +{
>>> +	WARN_ON(clk);
>>> +	return -1;
>>
>>     Shouldn't this be a proepr error code (-1 corresponds to -EPRERM)?
> 
> Could be ENODEV or EINVAL but all other stubs here and in ar7/clock.c
> use -1. Do you prefer it then to have it inconsistent with others?

I don't see where -1 is used, ar7/clock.c returns 0. Other drivers
either return 0 or EINVAL.

Since linux/clk.h returns 0 in the stub, I think 0 is the correct variant.