Re: [PATCH v2 15/20] drm/drv: Call drm_mode_config_create_state() by default

Thomas Zimmermann
2026-04-21T15:33:17Z

Am 21.04.26 um 15:38 schrieb Thomas Zimmermann:
> Hi
>
> Am 20.03.26 um 17:27 schrieb Maxime Ripard:
>> Almost all drivers, and our documented skeleton, call
>> drm_mode_config_reset() prior to calling drm_dev_register() to
>> initialize its DRM object states.
>>
>> Now that we have drm_mode_config_create_state() to create that initial
>> state if it doesn't exist, we can call it directly in
>> drm_dev_register(). That way, we know that the initial atomic state will
>> always be allocated without any boilerplate.
>>
>> Signed-off-by: Maxime Ripard <mripard@kernel.org>
>> ---
>>   drivers/gpu/drm/drm_drv.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
>> index
>> 2915118436ce8a6640cfb0c59936031990727ed1..820106d56ab399a39cac56d98662b5ddbcae8ded
>> 100644
>> --- a/drivers/gpu/drm/drm_drv.c
>> +++ b/drivers/gpu/drm/drm_drv.c
>> @@ -1097,10 +1097,14 @@ int drm_dev_register(struct drm_device *dev,
>> unsigned long flags)
>>         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
>>           ret = drm_modeset_register_all(dev);
>>           if (ret)
>>               goto err_unload;
>> +
>> +        ret = drm_mode_config_create_state(dev);
>> +        if (ret)
>> +            goto err_unload;
>
> Way too late. Lets rather go through drivers and call this where they
> currently call drm_mode_config_reset() for initialization. This can be
> a single-patch mass conversion IMHO.

On a second thought, can't we modify the suspend code and leave the
reset as-is for now?  I'd still be interested to use reset as a means of
initializing the hardware or loading state on probe. So keeping the
_reset() calls in place might be helpful for that.

What's the long-term plan here?

Best regards
Thomas

>
> Best regards
> Thomas
>
>>       }
>>       drm_panic_register(dev);
>>       drm_client_sysrq_register(dev);
>>         DRM_INFO("Initialized %s %d.%d.%d for %s on minor %d\n",
>>
>

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)