Re: [PATCH] drm/virtio: Open-code drm_simple_encoder_init()

[Thomas Zimmermann <tzimmermann@suse.de>]

Hi

Am 02.03.26 um 14:57 schrieb Dmitry Osipenko:
> On 3/2/26 16:48, Thomas Zimmermann wrote:
>> Hi
>>
>> Am 27.02.26 um 11:35 schrieb Hardik Phalet:
>>> drm_simple_encoder_init() is a thin wrapper around drm_encoder_init()
>>> that only provides a minimal drm_encoder_funcs instance with
>>> .destroy = drm_encoder_cleanup.
>>>
>>> Inline the helper in virtgpu_display.c and provide a local
>>> drm_encoder_funcs instance instead. This removes the unnecessary
>>> indirection and prepares for the eventual removal of
>>> drm_simple_encoder_init().
>>>
>>> No functional changes intended.
>>>
>>> Signed-off-by: Hardik Phalet <hardik.phalet@pm.me>
>>> ---
>>>    drivers/gpu/drm/virtio/virtgpu_display.c | 7 ++++++-
>>>    1 file changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/
>>> drm/virtio/virtgpu_display.c
>>> index f1dae9569805..8bd6cdc6c16e 100644
>>> --- a/drivers/gpu/drm/virtio/virtgpu_display.c
>>> +++ b/drivers/gpu/drm/virtio/virtgpu_display.c
>>> @@ -232,6 +232,10 @@ static enum drm_mode_status
>>> virtio_gpu_conn_mode_valid(struct drm_connector *con
>>>        return MODE_BAD;
>>>    }
>>>    +static const struct drm_encoder_funcs virtio_gpu_enc_cleanup_funcs = {
>>> +    .destroy = drm_encoder_cleanup
>>> +};
>>> +
>>>    static const struct drm_encoder_helper_funcs
>>> virtio_gpu_enc_helper_funcs = {
>>>        .mode_set   = virtio_gpu_enc_mode_set,
>>>        .enable     = virtio_gpu_enc_enable,
>>> @@ -306,7 +310,8 @@ static int vgdev_output_init(struct
>>> virtio_gpu_device *vgdev, int index)
>>>        if (vgdev->has_edid)
>>>            drm_connector_attach_edid_property(connector);
>>>    -    drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_VIRTUAL);
>>> +    drm_encoder_init(dev, encoder, &virtio_gpu_enc_cleanup_funcs,
>>> +             DRM_MODE_ENCODER_VIRTUAL, NULL);
>> This looks correct, but you should also remove the include statement at [1]
>>
>> [1] https://elixir.bootlin.com/linux/v6.19/source/drivers/gpu/drm/
>> virtio/virtgpu_display.c#L35
> The patch adds more lines than removes. What's wrong with
> drm_simple_encoder_init() and why it needs to be removed eventually?

I added it myself a few years ago in an attempt to save some lines of 
code. That was a mistake. It's a helper without any purpose. Helpers 
should do something.

Best regards
Thomas


>

-- 
--
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)