Re: [PATCH RFC v4 3/7] drm/atomic: Move framebuffer checks to helper

[Jessica Zhang <quic_jesszhan@quicinc.com>]

On 6/29/2023 5:43 PM, Dmitry Baryshkov wrote:
> On 30/06/2023 03:25, Jessica Zhang wrote:
>> Currently framebuffer checks happen directly in
>> drm_atomic_plane_check(). Move these checks into their own helper
>> method.
>>
>> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
>> ---
>>   drivers/gpu/drm/drm_atomic.c | 130 
>> ++++++++++++++++++++++++-------------------
>>   1 file changed, 74 insertions(+), 56 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
>> index b4c6ffc438da..404b984d2d9f 100644
>> --- a/drivers/gpu/drm/drm_atomic.c
>> +++ b/drivers/gpu/drm/drm_atomic.c
>> @@ -580,6 +580,76 @@ plane_switching_crtc(const struct drm_plane_state 
>> *old_plane_state,
>>       return true;
>>   }
>> +static int drm_atomic_check_fb(const struct drm_plane_state *state)
>> +{
>> +    struct drm_plane *plane = state->plane;
>> +    const struct drm_framebuffer *fb = state->fb;
>> +    struct drm_mode_rect *clips;
>> +
>> +    uint32_t num_clips;
>> +    unsigned int fb_width, fb_height;
>> +    int ret;
>> +
>> +    /* Check whether this plane supports the fb pixel format. */
>> +    ret = drm_plane_check_pixel_format(plane, fb->format->format,
>> +                       fb->modifier);
>> +
>> +    if (ret) {
>> +        drm_dbg_atomic(plane->dev,
>> +                   "[PLANE:%d:%s] invalid pixel format %p4cc, 
>> modifier 0x%llx\n",
>> +                   plane->base.id, plane->name,
>> +                   &fb->format->format, fb->modifier);
>> +        return ret;
>> +    }
>> +
>> +    fb_width = fb->width << 16;
>> +    fb_height = fb->height << 16;
>> +
>> +    /* Make sure source coordinates are inside the fb. */
>> +    if (state->src_w > fb_width ||
>> +        state->src_x > fb_width - state->src_w ||
>> +        state->src_h > fb_height ||
>> +        state->src_y > fb_height - state->src_h) {
>> +        drm_dbg_atomic(plane->dev,
>> +                   "[PLANE:%d:%s] invalid source coordinates "
>> +                   "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
>> +                   plane->base.id, plane->name,
>> +                   state->src_w >> 16,
>> +                   ((state->src_w & 0xffff) * 15625) >> 10,
>> +                   state->src_h >> 16,
>> +                   ((state->src_h & 0xffff) * 15625) >> 10,
>> +                   state->src_x >> 16,
>> +                   ((state->src_x & 0xffff) * 15625) >> 10,
>> +                   state->src_y >> 16,
>> +                   ((state->src_y & 0xffff) * 15625) >> 10,
>> +                   fb->width, fb->height);
>> +        return -ENOSPC;
>> +    }
>> +
>> +    clips = __drm_plane_get_damage_clips(state);
>> +    num_clips = drm_plane_get_damage_clips_count(state);
>> +
>> +    /* Make sure damage clips are valid and inside the fb. */
>> +    while (num_clips > 0) {
>> +        if (clips->x1 >= clips->x2 ||
>> +            clips->y1 >= clips->y2 ||
>> +            clips->x1 < 0 ||
>> +            clips->y1 < 0 ||
>> +            clips->x2 > fb_width ||
>> +            clips->y2 > fb_height) {
>> +            drm_dbg_atomic(plane->dev,
>> +                       "[PLANE:%d:%s] invalid damage clip %d %d %d 
>> %d\n",
>> +                       plane->base.id, plane->name, clips->x1,
>> +                       clips->y1, clips->x2, clips->y2);
>> +            return -EINVAL;
>> +        }
>> +        clips++;
>> +        num_clips--;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>>   /**
>>    * drm_atomic_plane_check - check plane state
>>    * @old_plane_state: old plane state to check
>> @@ -596,9 +666,6 @@ static int drm_atomic_plane_check(const struct 
>> drm_plane_state *old_plane_state,
>>       struct drm_plane *plane = new_plane_state->plane;
>>       struct drm_crtc *crtc = new_plane_state->crtc;
>>       const struct drm_framebuffer *fb = new_plane_state->fb;
>> -    unsigned int fb_width, fb_height;
>> -    struct drm_mode_rect *clips;
>> -    uint32_t num_clips;
>>       int ret;
>>       /* either *both* CRTC and FB must be set, or neither */
>> @@ -625,17 +692,6 @@ static int drm_atomic_plane_check(const struct 
>> drm_plane_state *old_plane_state,
>>           return -EINVAL;
>>       }
>> -    /* Check whether this plane supports the fb pixel format. */
>> -    ret = drm_plane_check_pixel_format(plane, fb->format->format,
>> -                       fb->modifier);
>> -    if (ret) {
>> -        drm_dbg_atomic(plane->dev,
>> -                   "[PLANE:%d:%s] invalid pixel format %p4cc, 
>> modifier 0x%llx\n",
>> -                   plane->base.id, plane->name,
>> -                   &fb->format->format, fb->modifier);
>> -        return ret;
>> -    }
>> -
>>       /* Give drivers some help against integer overflows */
>>       if (new_plane_state->crtc_w > INT_MAX ||
>>           new_plane_state->crtc_x > INT_MAX - (int32_t) 
>> new_plane_state->crtc_w ||
>> @@ -649,49 +705,11 @@ static int drm_atomic_plane_check(const struct 
>> drm_plane_state *old_plane_state,
>>           return -ERANGE;
>>       }
>> -    fb_width = fb->width << 16;
>> -    fb_height = fb->height << 16;
>> -    /* Make sure source coordinates are inside the fb. */
>> -    if (new_plane_state->src_w > fb_width ||
>> -        new_plane_state->src_x > fb_width - new_plane_state->src_w ||
>> -        new_plane_state->src_h > fb_height ||
>> -        new_plane_state->src_y > fb_height - new_plane_state->src_h) {
>> -        drm_dbg_atomic(plane->dev,
>> -                   "[PLANE:%d:%s] invalid source coordinates "
>> -                   "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
>> -                   plane->base.id, plane->name,
>> -                   new_plane_state->src_w >> 16,
>> -                   ((new_plane_state->src_w & 0xffff) * 15625) >> 10,
>> -                   new_plane_state->src_h >> 16,
>> -                   ((new_plane_state->src_h & 0xffff) * 15625) >> 10,
>> -                   new_plane_state->src_x >> 16,
>> -                   ((new_plane_state->src_x & 0xffff) * 15625) >> 10,
>> -                   new_plane_state->src_y >> 16,
>> -                   ((new_plane_state->src_y & 0xffff) * 15625) >> 10,
>> -                   fb->width, fb->height);
>> -        return -ENOSPC;
>> -    }
>> -
>> -    clips = __drm_plane_get_damage_clips(new_plane_state);
>> -    num_clips = drm_plane_get_damage_clips_count(new_plane_state);
>> -
>> -    /* Make sure damage clips are valid and inside the fb. */
>> -    while (num_clips > 0) {
>> -        if (clips->x1 >= clips->x2 ||
>> -            clips->y1 >= clips->y2 ||
>> -            clips->x1 < 0 ||
>> -            clips->y1 < 0 ||
>> -            clips->x2 > fb_width ||
>> -            clips->y2 > fb_height) {
>> -            drm_dbg_atomic(plane->dev,
>> -                       "[PLANE:%d:%s] invalid damage clip %d %d %d 
>> %d\n",
>> -                       plane->base.id, plane->name, clips->x1,
>> -                       clips->y1, clips->x2, clips->y2);
>> -            return -EINVAL;
>> -        }
>> -        clips++;
>> -        num_clips--;
>> +    if (fb) {
> 
> This doesn't only move code, but also changes semantics, making the 
> checks optional if no FB is provided. Consider moving the condition to 
> the next patch. Otherwise LGTM.

Hi Dmitry,

Sounds good.

Thanks,

Jessica Zhang

> 
>> +        ret = drm_atomic_check_fb(new_plane_state);
>> +        if (ret)
>> +            return ret;
>>       }
>>       if (plane_switching_crtc(old_plane_state, new_plane_state)) {
>>
> 
> -- 
> With best wishes
> Dmitry
>