drm/udl: Begin/end access to imported buffers in damage-handler

The damage-handler code now invokes dma_buf_{begin,end}_access()
for imported buffers. These calls were missing from the page-flip
and modesetting code paths. The patch also fixes an bug in the
original where an error code was overwritten by the result of
dma_buf_end_cpu_access().

v2:
	* only return an error code from dma_buf_end_cpu_access() if
	  no other error code has been set before

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191206085954.9697-7-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
index 482786e..0f83a6f 100644 (file)
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@@ -92,7 +92,8 @@ int udl_handle_damage(struct drm_framebuffer *fb, int x, int y,
 {
        struct drm_device *dev = fb->dev;
        struct udl_device *udl = to_udl(dev);
-       int i, ret;
+       struct dma_buf_attachment *import_attach = fb->obj[0]->import_attach;
+       int i, ret, tmp_ret;
        char *cmd;
        struct urb *urb;
        struct drm_rect clip;
@@ -117,15 +118,22 @@ int udl_handle_damage(struct drm_framebuffer *fb, int x, int y,
        else if ((clip.x2 > fb->width) || (clip.y2 > fb->height))
                return -EINVAL;
 
+       if (import_attach) {
+               ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
+                                              DMA_FROM_DEVICE);
+               if (ret)
+                       return ret;
+       }
+
        vaddr = drm_gem_shmem_vmap(fb->obj[0]);
        if (IS_ERR(vaddr)) {
                DRM_ERROR("failed to vmap fb\n");
-               return 0;
+               goto out_dma_buf_end_cpu_access;
        }
 
        urb = udl_get_urb(dev);
        if (!urb)
-               goto out;
+               goto out_drm_gem_shmem_vunmap;
        cmd = urb->transfer_buffer;
 
        for (i = clip.y1; i < clip.y2; i++) {
@@ -136,7 +144,7 @@ int udl_handle_damage(struct drm_framebuffer *fb, int x, int y,
                if (udl_render_hline(dev, log_bpp, &urb, (char *)vaddr,
                                     &cmd, byte_offset, dev_byte_offset,
                                     byte_width))
-                       goto out;
+                       goto out_drm_gem_shmem_vunmap;
        }
 
        if (cmd > (char *) urb->transfer_buffer) {
@@ -149,10 +157,19 @@ int udl_handle_damage(struct drm_framebuffer *fb, int x, int y,
        } else
                udl_urb_completion(urb);
 
-out:
+       ret = 0;
+
+out_drm_gem_shmem_vunmap:
        drm_gem_shmem_vunmap(fb->obj[0], vaddr);
+out_dma_buf_end_cpu_access:
+       if (import_attach) {
+               tmp_ret = dma_buf_end_cpu_access(import_attach->dmabuf,
+                                                DMA_FROM_DEVICE);
+               if (tmp_ret && !ret)
+                       ret = tmp_ret; /* only update ret if not set yet */
+       }
 
-       return 0;
+       return ret;
 }
 
 static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,
@@ -162,7 +179,6 @@ static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,
                                      unsigned num_clips)
 {
        struct udl_device *udl = fb->dev->dev_private;
-       struct dma_buf_attachment *import_attach;
        int i;
        int ret = 0;
 
@@ -175,15 +191,6 @@ static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,
        }
        spin_unlock(&udl->active_fb_16_lock);
 
-       import_attach = fb->obj[0]->import_attach;
-
-       if (import_attach) {
-               ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
-                                              DMA_FROM_DEVICE);
-               if (ret)
-                       goto unlock;
-       }
-
        for (i = 0; i < num_clips; i++) {
                ret = udl_handle_damage(fb, clips[i].x1, clips[i].y1,
                                        clips[i].x2 - clips[i].x1,
@@ -192,10 +199,6 @@ static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,
                        break;
        }
 
-       if (import_attach)
-               ret = dma_buf_end_cpu_access(import_attach->dmabuf,
-                                            DMA_FROM_DEVICE);
-
  unlock:
        drm_modeset_unlock_all(fb->dev);