Hello Thomas,
Thanks a lot for your feedback.
On 9/30/22 10:26, Thomas Zimmermann wrote:
> Hi
>
> Am 30.09.22 um 10:01 schrieb Javier Martinez Canillas:
>> The drm_atomic_helper_damage_merged() helper merges all the damage clips
>> into one rectangle. If there are multiple damage clips that aren't close
>> to each other, the resulting rectangle could be quite big.
>>
>> Instead of using that function helper, iterate over all the damage clips
>> and update them one by one.
>>
>> Suggested-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
>> Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
>> ---
>>
>> drivers/gpu/drm/solomon/ssd130x.c | 18 ++++++++++--------
>> 1 file changed, 10 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
>> index bc41a5ae810a..2428f1813a8d 100644
>> --- a/drivers/gpu/drm/solomon/ssd130x.c
>> +++ b/drivers/gpu/drm/solomon/ssd130x.c
>> @@ -578,21 +578,23 @@ static void ssd130x_primary_plane_helper_atomic_update(struct drm_plane *plane,
>> struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
>> struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
>> struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
>> + struct drm_atomic_helper_damage_iter iter;
>> struct drm_device *drm = plane->dev;
>> - struct drm_rect src_clip, dst_clip;
>> + struct drm_rect dst_clip;
>> + struct drm_rect damage;
>> int idx;
>>
>> - if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &src_clip))
>> - return;
>> -
>> dst_clip = plane_state->dst;
>> - if (!drm_rect_intersect(&dst_clip, &src_clip))
>> - return;
>> -
>> if (!drm_dev_enter(drm, &idx))
>> return;
>>
>> - ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &dst_clip);
>> + drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
>> + drm_atomic_for_each_plane_damage(&iter, &damage) {
>> + if (!drm_rect_intersect(&dst_clip, &damage))
>> + continue;
>
> dst_clip will be overwritten here. So need to init it within the loop first.
>
Oh, indeed. I'll move it inside the loop. Thanks for catching this.
>> +
>> + ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &damage);
>
> In simpledrm, we adjust the destination address with dst_clip like this:
>
> iosys_map_incr(&dst, drm_fb_clip_offset(sdev->pitch, sdev->format,
> &dst_clip));
>
> How does this work in ssd130x? You never use dst_clip to adjust to the
> changed location. Won't you have out-of-bounds writes on the device?
>
Right, in ssd130x what I do is:
static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_map *vmap,
struct drm_rect *rect)
{
struct iosys_map dst;
...
u8 *buf = NULL;
...
buf = kcalloc(dst_pitch, drm_rect_height(rect), GFP_KERNEL);
...
iosys_map_set_vaddr(&dst, buf);
drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect);
...
ssd130x_update_rect(ssd130x, buf, rect);
}
I understand that's correct too?
--
Best regards,
Javier Martinez Canillas
Core Platforms
Red Hat
