drm/udl: Unmap buffer object after damage update

Udl keeps a BO mapped for its entire lifetime if it has been used in a
damage update at least once. The BO's free callback release the mapping
before it frees the BO.

Change this behaviour to unmap immediately after the damage update, so
SHMEM's implementation of free can be used.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191114141025.32198-2-tzimmermann@suse.de

drivers/gpu/drm/udl/udl_fb.c

@@ -73,6 +73,7 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
 	struct urb *urb;
 	int aligned_x;
 	int log_bpp;
+	void *vaddr;
 
 	BUG_ON(!is_power_of_2(fb->base.format->cpp[0]));
 	log_bpp = __ffs(fb->base.format->cpp[0]);
@@ -80,14 +81,10 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
 	if (!fb->active_16)
 		return 0;
 
-	if (!fb->shmem->vaddr) {
-		void *vaddr;
-
-		vaddr = drm_gem_shmem_vmap(&fb->shmem->base);
-		if (IS_ERR(vaddr)) {
-			DRM_ERROR("failed to vmap fb\n");
-			return 0;
-		}
+	vaddr = drm_gem_shmem_vmap(&fb->shmem->base);
+	if (IS_ERR(vaddr)) {
+		DRM_ERROR("failed to vmap fb\n");
+		return 0;
 	}
 
 	aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
@@ -96,22 +93,23 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
 
 	if ((width <= 0) ||
 	    (x + width > fb->base.width) ||
-	    (y + height > fb->base.height))
-		return -EINVAL;
+	    (y + height > fb->base.height)) {
+		ret = -EINVAL;
+		goto err_drm_gem_shmem_vunmap;
+	}
 
 	start_cycles = get_cycles();
 
 	urb = udl_get_urb(dev);
 	if (!urb)
-		return 0;
+		goto out;
 	cmd = urb->transfer_buffer;
 
 	for (i = y; i < y + height ; i++) {
 		const int line_offset = fb->base.pitches[0] * i;
 		const int byte_offset = line_offset + (x << log_bpp);
 		const int dev_byte_offset = (fb->base.width * i + x) << log_bpp;
-		if (udl_render_hline(dev, log_bpp, &urb,
-				     (char *) fb->shmem->vaddr,
+		if (udl_render_hline(dev, log_bpp, &urb, (char *)vaddr,
 				     &cmd, byte_offset, dev_byte_offset,
 				     width << log_bpp,
 				     &bytes_identical, &bytes_sent))
@@ -138,7 +136,14 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
 		    >> 10)), /* Kcycles */
 		   &udl->cpu_kcycles_used);
 
+out:
+	drm_gem_shmem_vunmap(&fb->shmem->base, vaddr);
+
 	return 0;
+
+err_drm_gem_shmem_vunmap:
+	drm_gem_shmem_vunmap(&fb->shmem->base, vaddr);
+	return ret;
 }
 
 static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,