Re: [PATCH v9 2/6] drm/log: Introduce a new boot logger to draw the kmsg on the screen

[Jocelyn Falempe <jfalempe@redhat.com>]

On 18/12/2024 13:25, Markus Elfring wrote:
> …
>> +++ b/drivers/gpu/drm/clients/drm_log.c
>> @@ -0,0 +1,370 @@
> …
>> +static int drm_log_count_modeset(struct drm_client_dev *client)
>> +{
>> +	struct drm_mode_set *mode_set;
>> +	int count = 0;
>> +
>> +	mutex_lock(&client->modeset_mutex);
>> +	drm_client_for_each_modeset(mode_set, client)
>> +		count++;
>> +	mutex_unlock(&client->modeset_mutex);
>> +	return count;
>> +}
> …
> 
> Under which circumstances would you become interested to apply a statement
> like “guard(mutex)(&client->modeset_mutex);”?
> https://elixir.bootlin.com/linux/v6.13-rc3/source/include/linux/mutex.h#L201

Ok, I didn't know about this new syntax, thanks for pointing this to me.
Regarding drm_log, I kept the mutex usage simple, as there is only one 
mutex_lock() and one mutex_unlock() in each function, which means there 
is not much benefit to use the guard syntax.
I will keep that in mind, and if there is a need to have more complex 
mutex handling, I will probably use this.

Best regards,

-- 

Jocelyn
> 
> Regards,
> Markus
>