Re: [PATCH 5/9] drm/pl111: replace struct drm_simple_display_pipe with regular atomic helpers

["Ze Huang" <ze.huang@xxxxxxxxxxxxxxxx>]

On Wed Jul 8, 2026 at 9:03 PM CST, Thomas Zimmermann wrote:
>
>
> Am 04.07.26 um 20:31 schrieb Ze Huang:
>> Replace PL111 simple display pipe with explicit plane, CRTC and encoder
>> objects.
>>
>> Keep existing hardware programming and vblank behavior, and install GEM
>> framebuffer prepare helper explicitly.
>>
>> Signed-off-by: Ze Huang <ze.huang@xxxxxxxxxxxxxxxx>
>> ---
>>   drivers/gpu/drm/pl111/pl111_display.c | 174 
>> ++++++++++++++++++++++++++--------
>>   drivers/gpu/drm/pl111/pl111_drm.h     |   5 +-
>>   drivers/gpu/drm/pl111/pl111_drv.c     |   3 +-
>>   3 files changed, 136 insertions(+), 46 deletions(-)
>>

[ ... ]

>> -static int pl111_display_check(struct drm_simple_display_pipe *pipe,
>> -                           struct drm_plane_state *pstate,
>> -                           struct drm_crtc_state *cstate)
>> +static int pl111_plane_helper_atomic_check(struct drm_plane *plane,
>> +                                       struct drm_atomic_commit *state)
>>   {
>> -    const struct drm_display_mode *mode = &cstate->mode;
>> -    struct drm_framebuffer *old_fb = pipe->plane.state->fb;
>> +    struct drm_plane_state *pstate = drm_atomic_get_new_plane_state(state, 
>> plane);
>> +    struct drm_crtc *crtc = pstate->crtc;
>> +    struct drm_crtc_state *cstate;
>> +    const struct drm_display_mode *mode;
>> +    struct drm_framebuffer *old_fb = plane->state->fb;
>>      struct drm_framebuffer *fb = pstate->fb;
>> +    int ret;
>> +
>> +    if (!crtc)
>> +            return 0;
>> +
>> +    cstate = drm_atomic_get_new_crtc_state(state, crtc);
>> +    if (!cstate)
>> +            return 0;
>> +
>> +    ret = drm_atomic_helper_check_plane_state(pstate, cstate,
>> +                                              DRM_PLANE_NO_SCALING,
>> +                                              DRM_PLANE_NO_SCALING,
>> +                                              false, false);
>
> This is another case of _check_plane_state() running conditionally.
>

Acknowledged

>> +    if (ret)
>> +            return ret;
>> +
>> +    if (!pstate->visible)
>> +            return 0;
>> +
>> +    mode = &cstate->mode;
>>   
>>      if (mode->hdisplay % 16)
>>              return -EINVAL;
>> @@ -117,16 +140,14 @@ static int pl111_display_check(struct 
>> drm_simple_display_pipe *pipe,
>>      return 0;
>>   }

[ ... ]