[PATCH 1/2] of: implement new of_device_ensured_probed_by_alias_stem

[Andrej Picej]

On 15. 03. 22 15:29, Ahmad Fatoum wrote:
> On 15.03.22 15:16, Ahmad Fatoum wrote:
>> Hello Andrej,
>>
>> On 15.03.22 14:39, Andrej Picej wrote:
>>> Function first goes through all the aliases which have the given stem.
>>> It then ensures that all the devices hiding under these aliases are
>>> probed.
>>>
>>> Signed-off-by: Andrej Picej <andrej.picej at norik.com>
>>> ---
>>>   drivers/of/base.c | 28 ++++++++++++++++++++++++++++
>>>   include/of.h      |  6 ++++++
>>>   2 files changed, 34 insertions(+)
>>>
>>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>>> index 80465d6d50..055dba97ab 100644
>>> --- a/drivers/of/base.c
>>> +++ b/drivers/of/base.c
>>> @@ -274,6 +274,34 @@ int of_alias_get_id_from(struct device_node *root, struct device_node *np,
>>>   }
>>>   EXPORT_SYMBOL_GPL(of_alias_get_id_from);
>>>   
>>> +/**
>>> + * of_device_ensured_probed_by_alias_stem - Ensure all devices with alias base name
>>> + * are probed
>>> + * @stem:	Alias stem of the given device_node
>>> + *
>>> + * The function ensures all devices with the given alias stem are probed.
>>> + *
>>> + * Returns 0 on success or error code.
>>> + */
>>> +int of_device_ensured_probed_by_alias_stem(const char *stem)
>>> +{
>>> +	struct alias_prop *app;
>>> +	int id = -ENODEV;
>>> +	int ret;
>>
>> Can you early exit here if (!deep_probe_is_supported())?
>>
>> This saves non-deep probe users the hassle of needless iteration
>> and string comparisons.
>>
>>> +
>>> +	list_for_each_entry(app, &aliases_lookup, link) {
> 
> Corner case: aliases in DT are not sorted, so
> 
> &{/aliases} { gpio1 = &pmic_gpio; gpio0 = &gpio1; };
> 
> may result in pmic_gpio being probed first..
True
> 
> Could be resolved by sorting aliases on insertion though. hmm..

Ok I will check things up and send a v2.

Thanks for review.
> 
>>> +		if (of_node_cmp(app->stem, stem) != 0)
>>> +			continue;
>>> +
>>> +		ret = of_device_ensure_probed(app->np);
>>> +		if (ret)
>>> +			return ret;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(of_device_ensured_probed_by_alias_stem);
>>> +
>>>   const char *of_alias_get(struct device_node *np)
>>>   {
>>>   	struct alias_prop *app;
>>> diff --git a/include/of.h b/include/of.h
>>> index 216d0ee763..95817c58a4 100644
>>> --- a/include/of.h
>>> +++ b/include/of.h
>>> @@ -261,6 +261,7 @@ extern void of_alias_scan(void);
>>>   extern int of_alias_get_id(struct device_node *np, const char *stem);
>>>   extern int of_alias_get_id_from(struct device_node *root, struct device_node *np,
>>>   				const char *stem);
>>> +extern int of_device_ensured_probed_by_alias_stem(const char *stem);
>>>   extern const char *of_alias_get(struct device_node *np);
>>>   extern int of_modalias_node(struct device_node *node, char *modalias, int len);
>>>   
>>> @@ -750,6 +751,11 @@ static inline int of_alias_get_id_from(struct device_node *root, struct device_n
>>>   	return -ENOSYS;
>>>   }
>>>   
>>> +static int of_device_ensured_probed_by_aliases(const char *stem)
>>> +{
>>> +	return -ENOSYS;
>>> +}
>>> +
>>>   static inline const char *of_alias_get(struct device_node *np)
>>>   {
>>>   	return NULL;
>>
>>
> 
>