Synchronize CPU access to GEM BOs with other drivers when updating the screen buffer. Imported DMA buffers might otherwise contain stale data. Suggested-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx> --- drivers/gpu/drm/solomon/ssd130x.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c index a537692100d1..bc41a5ae810a 100644 --- a/drivers/gpu/drm/solomon/ssd130x.c +++ b/drivers/gpu/drm/solomon/ssd130x.c @@ -555,11 +555,18 @@ static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_m if (!buf) return -ENOMEM; + ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE); + if (ret) + goto out_free; + iosys_map_set_vaddr(&dst, buf); drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect); + drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE); + ssd130x_update_rect(ssd130x, buf, rect); +out_free: kfree(buf); return ret; -- 2.37.3