[PATCH 1/3] drm/panic: Add drm_panic_is_enabled()

[Jocelyn Falempe]

On 19/07/2024 12:18, Imre Deak wrote:
> Hi,
> 
> On Wed, Jul 17, 2024 at 10:48:39AM +0200, Jocelyn Falempe wrote:
>> It allows to check if the drm device supports drm_panic.
>> Prepare the work to have better integration with fbcon and vtconsole.
>>
>> Signed-off-by: Jocelyn Falempe <jfalempe at redhat.com>
>> ---
>>   drivers/gpu/drm/drm_panic.c | 20 ++++++++++++++++++++
>>   include/drm/drm_panic.h     |  2 ++
>>   2 files changed, 22 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
>> index 948aed00595e..d9a25c2d0a65 100644
>> --- a/drivers/gpu/drm/drm_panic.c
>> +++ b/drivers/gpu/drm/drm_panic.c
>> @@ -703,6 +703,26 @@ static void debugfs_register_plane(struct drm_plane *plane, int index)
>>   static void debugfs_register_plane(struct drm_plane *plane, int index) {}
>>   #endif /* CONFIG_DRM_PANIC_DEBUG */
>>   
>> +/**
>> + * drm_panic_is_enabled
>> + * @dev: the drm device that may supports drm_panic
>> + *
>> + * returns true if the drm device supports drm_panic
>> + */
>> +bool drm_panic_is_enabled(struct drm_device *dev)
>> +{
>> +	struct drm_plane *plane;
>> +
>> +	if (!dev->mode_config.num_total_plane)
>> +		return false;
>> +
>> +	drm_for_each_plane(plane, dev)
>> +		if (plane->helper_private && plane->helper_private->get_scanout_buffer)
>> +			return true;
>> +	return false;
>> +}
>> +EXPORT_SYMBOL(drm_panic_is_enabled);
>> +
>>   /**
>>    * drm_panic_register() - Initialize DRM panic for a device
>>    * @dev: the drm device on which the panic screen will be displayed.
>> diff --git a/include/drm/drm_panic.h b/include/drm/drm_panic.h
>> index 73bb3f3d9ed9..c3a358dc3e27 100644
>> --- a/include/drm/drm_panic.h
>> +++ b/include/drm/drm_panic.h
>> @@ -148,11 +148,13 @@ struct drm_scanout_buffer {
>>   
>>   #ifdef CONFIG_DRM_PANIC
>>   
>> +bool drm_panic_is_enabled(struct drm_device *dev);
>>   void drm_panic_register(struct drm_device *dev);
>>   void drm_panic_unregister(struct drm_device *dev);
>>   
>>   #else
>>   
>> +bool drm_panic_is_enabled(struct drm_device *dev) {return false; }
> 
> This was moved to drivers/gpu/drm/drm_crtc_internal.h in the applied
> version and I can't find that version on the mailing list; imo this kind
> of change requires a resend.

Sorry, I though that was a minor change, but I messed it up.

Yes sending to the mailing list also triggers the CI, and checks for 
simple errors like this, I will send a fix shortly.

> 
> Also, the above breaks CONFIG_DRM_PANIC=n builds:
> 
> In file included from drivers/gpu/drm/drm_atomic_uapi.c:43:
> drivers/gpu/drm/drm_crtc_internal.h:322:6: error: no previous prototype for ‘drm_panic_is_enabled’ [-Werror=missing-prototypes]
>    322 | bool drm_panic_is_enabled(struct drm_device *dev) {return false; }
> 
> Stubs like the above must be an inline function.
> 
>>   static inline void drm_panic_register(struct drm_device *dev) {}
>>   static inline void drm_panic_unregister(struct drm_device *dev) {}
>>   
>> -- 
>> 2.45.2
>>
>