Re: [PATCH 1/1] power/supply/powersupply_sysfs: Add of_node name to uevent message if available

[Richard Tresidder <rtresidd@electromag.com.au>]

As per David's suggestion
I did a quick refactor of the of_device_uevent() call to handle a 
device_node "of_device_node_uevent()" instead of a device and ran into a 
problem.
Was getting stack dumps (via a WARN message) generated out of 
add_uevent_var() for any power supply device.
It was trigered in the first check of
     if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
     ...
of that add_uevent_var function.
So it looks like to many value pairs were being shoved into the event?
envp array is set to a fixed length of 32 via the UEVENT_NUM_ENVP value 
in kobject.h

I verified it had nothing to do with with the refactor by backing it out 
and simply adding a few more
dummy add_uevent_var calls in the power_supply_uevent call..

so there appears to be a hard limit on this.. which we are very near for 
the power supply stuff.

Thoughts?

Thanks
    Richard Tresidder

On 26/07/2019 12:51 pm, Richard Tresidder wrote:
> Hi David
>   That call requires a struct device *
> But the of_node pointer is located in the struct power_supply
> Seems the of_node value in the base device* is null, and often is.
> I find it hard at times to figure out which one of these to reference 
> as things seem to be duplicated in a lot of places..
>
> Should that call potentially be refactored to take a device_node * 
> instead of a device *
>
> **
> Regards
>    Richard Tresidder
>
> On 26/07/2019 10:40 am, Richard Tresidder wrote:
>> Hi David
>>   That it would be. I wasn't aware of that call.
>> I'll give it a crack and send in a new version of the patch.
>>
>> Cheers
>>   Richard Tresidder
>>
>> Richard Tresidder
>> On 25/07/2019 10:08 pm, David Lechner wrote:
>>> On 7/25/19 2:47 AM, Richard Tresidder wrote:
>>>> If the of_node name of the supply is available from the devicetree 
>>>> binding
>>>> then include it under the var POWER_SUPPLY_OF_NODE_NAME.
>>>> This helps where a consistent name is known via the device tree 
>>>> binding
>>>> but it is hard to identify based on the usual enumeration process.
>>>>
>>>
>>> Would it be possible to use of_device_uevent() instead of 
>>> introducing a new
>>> property?
>>>
>>>
>>>
>>
>>
>>
>
>
>