drm/udl: Add reset_resume

Implement the reset_resume callback of struct usb_driver. Set the
standard channel when called.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220908095115.23396-3-tiwai@suse.de

drivers/gpu/drm/udl/udl_drv.c

@@ -32,6 +32,16 @@ static int udl_usb_resume(struct usb_interface *interface)
 	return drm_mode_config_helper_resume(dev);
 }
 
+static int udl_usb_reset_resume(struct usb_interface *interface)
+{
+	struct drm_device *dev = usb_get_intfdata(interface);
+	struct udl_device *udl = to_udl(dev);
+
+	udl_select_std_channel(udl);
+
+	return drm_mode_config_helper_resume(dev);
+}
+
 /*
  * FIXME: Dma-buf sharing requires DMA support by the importing device.
  *        This function is a workaround to make USB devices work as well.
@@ -140,6 +150,7 @@ static struct usb_driver udl_driver = {
 	.disconnect = udl_usb_disconnect,
 	.suspend = udl_usb_suspend,
 	.resume = udl_usb_resume,
+	.reset_resume = udl_usb_reset_resume,
 	.id_table = id_table,
 };
 module_usb_driver(udl_driver);

drivers/gpu/drm/udl/udl_drv.h

@@ -95,6 +95,7 @@ int udl_render_hline(struct drm_device *dev, int log_bpp, struct urb **urb_ptr,
 		     u32 byte_offset, u32 device_byte_offset, u32 byte_width);
 
 int udl_drop_usb(struct drm_device *dev);
+int udl_select_std_channel(struct udl_device *udl);
 
 #define CMD_WRITE_RAW8   "\xAF\x60" /**< 8 bit raw write command. */
 #define CMD_WRITE_RL8    "\xAF\x61" /**< 8 bit run length command. */

drivers/gpu/drm/udl/udl_main.c

@@ -92,7 +92,7 @@ static int udl_parse_vendor_descriptor(struct udl_device *udl)
 /*
  * Need to ensure a channel is selected before submitting URBs
  */
-static int udl_select_std_channel(struct udl_device *udl)
+int udl_select_std_channel(struct udl_device *udl)
 {
 	static const u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
 					 0x1C, 0x88, 0x5E, 0x15,