Hi

Am 25.07.22 um 17:46 schrieb Javier Martinez Canillas:
> On 7/20/22 16:27, Thomas Zimmermann wrote:
>> Replace the simple-KMS helpers with the regular atomic helpers. The
>> regular helpers are better architectured and therefore allow for easier
>> code sharing among drivers. No functional changes.
>>
> 
> Acked-by: Javier Martinez Canillas <javierm@redhat.com>
> 
> But I've a question below...
>   
>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>> ---
>>   drivers/gpu/drm/tiny/simpledrm.c | 283 ++++++++++++++++++++-----------
>>   1 file changed, 180 insertions(+), 103 deletions(-)
> 
> [...]
> 
>> +static void simpledrm_crtc_helper_atomic_enable(struct drm_crtc *crtc,
>> +						struct drm_atomic_state *old_state)
>> +{
>> +	/*
>> +	 * Always enabled; screen updates are performed by
>> +	 * the primary plane's atomic_update function.
>> +	 */
>> +}
>> +
>> +static void simpledrm_crtc_helper_atomic_disable(struct drm_crtc *crtc,
>> +						 struct drm_atomic_state *old_state)
>> +{
>> +	/*
>> +	 * Always enabled; disabling clears the screen in the
>> +	 * primary plane's atomic_disable function.
>> +	 */
>> +}
> 
> ...do we really need to have these ? Can't we just not set them ?
> 
>> +
>> +static const struct drm_crtc_helper_funcs simpledrm_crtc_helper_funcs = {
>> +	.mode_valid = simpledrm_crtc_helper_mode_valid,
>> +	.atomic_check = simpledrm_crtc_helper_atomic_check,
>> +	.atomic_enable = simpledrm_crtc_helper_atomic_enable,
>> +	.atomic_disable = simpledrm_crtc_helper_atomic_disable,
>> +};
>> +
> looking at https://elixir.bootlin.com/linux/latest/source/include/drm/drm_modeset_helper_vtables.h#L703
> that says the .atomic_{en,dis}able handlers are optional.
> 

The code also looks like we don't need the helpers. I mostly added them 
for the comments they contain, but I can also add those next to 
simpledrm_crtc_helper_funcs.

Best regards
Thomas


-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
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