Re: [PATCH v2] Bluetooth: qca: set power_ctrl_enabled on NULL returned by gpiod_get_optional()

From: Wren Turkal <wt@penguintechs.org>
To: quic_zijuhu <quic_zijuhu@quicinc.com>,
	Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>,
	Marcel Holtmann <marcel@holtmann.org>,
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] Bluetooth: qca: set power_ctrl_enabled on NULL returned by gpiod_get_optional()
Date: Wed, 24 Apr 2024 06:40:24 -0700	[thread overview]
Message-ID: <854acf89-43a4-42f8-b8ea-8f0c108f3aec@penguintechs.org> (raw)
In-Reply-To: <97ecc6fc-6b0e-4028-ac06-1952f133bd2a@quicinc.com>

On 4/24/24 6:36 AM, quic_zijuhu wrote:
> On 4/24/2024 9:31 PM, Wren Turkal wrote:
>> On 4/24/24 6:22 AM, quic_zijuhu wrote:
>>> On 4/24/2024 9:18 PM, Bartosz Golaszewski wrote:
>>>> On Wed, 24 Apr 2024 at 15:10, Wren Turkal <wt@penguintechs.org> wrote:
>>>>>
>>>>> On 4/24/24 5:29 AM, Bartosz Golaszewski wrote:
>>>>>> From: Bartosz Golaszewski<bartosz.golaszewski@linaro.org>
>>>>>>
>>>>>> Any return value from gpiod_get_optional() other than a pointer to a
>>>>>> GPIO descriptor or a NULL-pointer is an error and the driver should
>>>>>> abort probing. That being said: commit 56d074d26c58 ("Bluetooth:
>>>>>> hci_qca:
>>>>>> don't use IS_ERR_OR_NULL() with gpiod_get_optional()") no longer sets
>>>>>> power_ctrl_enabled on NULL-pointer returned by
>>>>>> devm_gpiod_get_optional(). Restore this behavior but bail-out on
>>>>>> errors.
>>>>>> While at it: also bail-out on error returned when trying to get the
>>>>>> "swctrl" GPIO.
>>>>>>
>>>>>> Reported-by: Wren Turkal<wt@penguintechs.org>
>>>>>> Reported-by: Zijun Hu<quic_zijuhu@quicinc.com>
>>>>>> Closes:https://lore.kernel.org/linux-bluetooth/1713449192-25926-2-git-send-email-quic_zijuhu@quicinc.com/
>>>>>> Fixes: 56d074d26c58 ("Bluetooth: hci_qca: don't use
>>>>>> IS_ERR_OR_NULL() with gpiod_get_optional()")
>>>>>> Reviewed-by: Krzysztof Kozlowski<krzysztof.kozlowski@linaro.org>
>>>>>> Signed-off-by: Bartosz Golaszewski<bartosz.golaszewski@linaro.org>
>>>>>
>>>>> Tested-by: "Wren Turkal" <wt@penguintechs.org>
>>>>>
>>>>>
>>>>> Like this?
>>>>
>>>> Yes, awesome, thanks.
>>>>
>>>> This is how reviewing works too in the kernel, look at what Krzysztof
>>>> did under v1, he just wrote:
>>>>
>>>> Reviewed-by: Krzysztof Kozlowski<krzysztof.kozlowski@linaro.org>
>>>>
>>> v1 have obvious something wrong as i pointed and verified.
>>> so i think it is not suitable to attach v1's review-by tag to v2 anyway.
>>
>> @Zijun, your concern is that current DTs may not define the gpio and
>> this will cause the bluetooth not to work?
>>
>> Would that not more appropriately be fixed by machine-specific fixups
>> for the DT?
>>
> for lunched production, it is difficult or not possible to change such
> config.

I am not talking about the DT in the device. I am talking about the 
mechanism the kernel has for applying fixups to DTs.

If a dev builds a new kernel for a dev and finds it not to work, the 
kernel would then have a fixup added, like described here: 
https://docs.kernel.org/devicetree/usage-model.html#platform-identification

> 
>>>
>>>> And mailing list tools will pick it up.
>>>>
>>>> Bartosz
>>>
>>
> 

-- 
You're more amazing than you think!