Re: [PATCH] regmap: debugfs: Fix a boot time crash with early regmap init

[Tero Kristo <t-kristo@ti.com>]

On 10/24/2013 12:18 PM, Mark Brown wrote:
> On Thu, Oct 24, 2013 at 12:07:48PM +0300, Tero Kristo wrote:
>
>> +	if (!regmap_debugfs_root) {
>> +		struct regmap_debugfs_node *node;
>> +		node = kzalloc(sizeof(*node), GFP_KERNEL);
>> +		if (!node)
>> +			return;
>> +		node->map = map;
>> +		node->name = name;
>> +		list_add(&node->link, &regmap_debugfs_early);
>> +		return;
>> +	}
>> +
>
> init is somewhat parallel so I'd be happier if we locked the list to
> make sure that we don't corrupt the list.

Ok, I added a mutex for protection (later registration might take some 
time so didn't want to use spinlock.)

> We also need something to handle removal of items from the list if the
> regmap is destroyed prior to the initcall running (for example in error
> handling cases), otherwise we could end up creating debugfs files
> pointing at devices that no longer exist.

Added cleanup for the list in the regmap_debugfs_exit() call. Sending v2 
shortly.

-Tero