[PATCH V2 4/4] pinctrl: add one more "const" for generic function groups

[Rafał Miłecki]

On 18.01.2022 08:02, Uwe Kleine-König wrote:
> On Tue, Jan 11, 2022 at 05:51:44PM +0100, Rafał Miłecki wrote:
>> On 11.01.2022 16:34, Nathan Chancellor wrote:
>>> On Thu, Dec 16, 2021 at 05:22:06PM +0100, Rafał Miłecki wrote:
>>>> From: Rafał Miłecki <rafal at milecki.pl>
>>>>
>>>> Generic code doesn't modify those strings and .get_function_groups
>>>> callback has that extra "const" as well. This allows more flexibility in
>>>> GENERIC_PINMUX_FUNCTIONS users.
>>>>
>>>> Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
>>>> ---
>>>>    drivers/pinctrl/pinmux.c | 2 +-
>>>>    drivers/pinctrl/pinmux.h | 4 ++--
>>>>    2 files changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
>>>> index 6cdbd9ccf2f0..f94d43b082d9 100644
>>>> --- a/drivers/pinctrl/pinmux.c
>>>> +++ b/drivers/pinctrl/pinmux.c
>>>> @@ -875,7 +875,7 @@ EXPORT_SYMBOL_GPL(pinmux_generic_get_function);
>>>>     */
>>>>    int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
>>>>    				const char *name,
>>>> -				const char **groups,
>>>> +				const char * const *groups,
>>>>    				const unsigned int num_groups,
>>>>    				void *data)
>>>>    {
>>>> diff --git a/drivers/pinctrl/pinmux.h b/drivers/pinctrl/pinmux.h
>>>> index 78c3a31be882..72fcf03eaa43 100644
>>>> --- a/drivers/pinctrl/pinmux.h
>>>> +++ b/drivers/pinctrl/pinmux.h
>>>> @@ -129,7 +129,7 @@ static inline void pinmux_init_device_debugfs(struct dentry *devroot,
>>>>     */
>>>>    struct function_desc {
>>>>    	const char *name;
>>>> -	const char **group_names;
>>>> +	const char * const *group_names;
>>>>    	int num_group_names;
>>>>    	void *data;
>>>>    };
>>>> @@ -150,7 +150,7 @@ struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
>>>>    int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
>>>>    				const char *name,
>>>> -				const char **groups,
>>>> +				const char * const *groups,
>>>>    				unsigned const num_groups,
>>>>    				void *data);
>>>> -- 
>>>> 2.31.1
>>>>
>>>>
>>>
>>> I have not seen this reported yet, even though it has been broken for a
>>> couple of weeks now. I see the following error in -next:
>>>
>>> $ make -skj"$(nproc)" ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- allmodconfig drivers/pinctrl/pinctrl-thunderbay.o
>>> drivers/pinctrl/pinctrl-thunderbay.c: In function ‘thunderbay_add_functions’:
>>> drivers/pinctrl/pinctrl-thunderbay.c:815:29: error: assignment discards ‘const’ qualifier from pointer target type [-Werror=discarded-qualifiers]
>>>     815 |                         grp = func->group_names;
>>>         |                             ^
>>> cc1: all warnings being treated as errors
>>>
>>> Looks like something like the third patch of the series is needed for
>>> the Thunderbay driver, which it appears was in development at the same
>>> time as this series.
>>
>> Correct, this driver didn't exist in Linus's tree when I developed my changes.
> 
> I stumbled above this issue, too. For the record, this patch fixes the
> build issue:

[PATCH 5.17 1/2] pinctrl: thunderbay: comment process of building functions a bit
[PATCH 5.17 2/2] pinctrl: thunderbay: rework loops looking for groups names
https://patchwork.ozlabs.org/project/linux-gpio/list/?series=280568

Patches already queued in the:
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git/log/?h=fixes