Call struct fb_ops.fb_sync in drm_fbdev_{read,write}() to mimic the behavior of fbdev. Fbdev implementations of fb_read and fb_write in struct fb_ops invoke fb_sync to synchronize with outstanding operations before I/O. Doing the same in DRM implementations will allow us to use them throughout DRM drivers. Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx> --- drivers/gpu/drm/drm_fb_helper.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index f6d22cc4cd876..379e0d2f67198 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -2246,6 +2246,9 @@ static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf, if (total_size - count < pos) count = total_size - pos; + if (info->fbops->fb_sync) + info->fbops->fb_sync(info); + if (drm_fbdev_use_iomem(info)) ret = fb_read_screen_base(info, buf, count, pos); else @@ -2327,6 +2330,9 @@ static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, count = total_size - pos; } + if (info->fbops->fb_sync) + info->fbops->fb_sync(info); + /* * Copy to framebuffer even if we already logged an error. Emulates * the behavior of the original fbdev implementation. -- 2.38.0