1 files changed, 45 insertions, 13 deletions

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index d2eb9066e4dc..d4b023d4de7c 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -79,13 +79,14 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 	if (likely(ret == size))
 		return 0;
 
-	dev_err(&dev->udev->dev,
-		"Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n",
-		uvc_query_name(query), cs, unit, ret, size);
-
-	if (ret != -EPIPE)
-		return ret;
+	if (ret != -EPIPE) {
+		dev_err(&dev->udev->dev,
+			"Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n",
+			uvc_query_name(query), cs, unit, ret, size);
+		return ret < 0 ? ret : -EPIPE;
+	}
 
+	/* Reuse data[0] to request the error code. */
 	tmp = *(u8 *)data;
 
 	ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum,
@@ -107,7 +108,7 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 	case 1: /* Not ready */
 		return -EBUSY;
 	case 2: /* Wrong state */
-		return -EILSEQ;
+		return -EACCES;
 	case 3: /* Power */
 		return -EREMOTE;
 	case 4: /* Out of range */
@@ -129,12 +130,13 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 	return -EPIPE;
 }
 
+static const struct usb_device_id elgato_cam_link_4k = {
+	USB_DEVICE(0x0fd9, 0x0066)
+};
+
 static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
 	struct uvc_streaming_control *ctrl)
 {
-	static const struct usb_device_id elgato_cam_link_4k = {
-		USB_DEVICE(0x0fd9, 0x0066)
-	};
 	struct uvc_format *format = NULL;
 	struct uvc_frame *frame = NULL;
 	unsigned int i;
@@ -297,7 +299,7 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
 		dev_err(&stream->intf->dev,
 			"Failed to query (%u) UVC %s control : %d (exp. %u).\n",
 			query, probe ? "probe" : "commit", ret, size);
-		ret = -EIO;
+		ret = (ret == -EPROTO) ? -EPROTO : -EIO;
 		goto out;
 	}
 
@@ -516,7 +518,9 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
 
 	/*
 	 * To limit the amount of data, drop SCRs with an SOF identical to the
-	 * previous one.
+	 * previous one. This filtering is also needed to support UVC 1.5, where
+	 * all the data packets of the same frame contains the same SOF. In that
+	 * case only the first one will match the host_sof.
 	 */
 	dev_sof = get_unaligned_le16(&data[header_size - 2]);
 	if (dev_sof == stream->clock.last_sof)
@@ -1352,7 +1356,9 @@ static void uvc_video_decode_meta(struct uvc_streaming *stream,
 	if (has_scr)
 		memcpy(stream->clock.last_scr, scr, 6);
 
-	memcpy(&meta->length, mem, length);
+	meta->length = mem[0];
+	meta->flags  = mem[1];
+	memcpy(meta->buf, &mem[2], length - 2);
 	meta_buf->bytesused += length + sizeof(meta->ns) + sizeof(meta->sof);
 
 	uvc_dbg(stream->dev, FRAME,
@@ -1965,6 +1971,17 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream,
 			"Selecting alternate setting %u (%u B/frame bandwidth)\n",
 			altsetting, best_psize);
 
+		/*
+		 * Some devices, namely the Logitech C910 and B910, are unable
+		 * to recover from a USB autosuspend, unless the alternate
+		 * setting of the streaming interface is toggled.
+		 */
+		if (stream->dev->quirks & UVC_QUIRK_WAKE_AUTOSUSPEND) {
+			usb_set_interface(stream->dev->udev, intfnum,
+					  altsetting);
+			usb_set_interface(stream->dev->udev, intfnum, 0);
+		}
+
 		ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);
 		if (ret < 0)
 			return ret;
@@ -2121,6 +2138,21 @@ int uvc_video_init(struct uvc_streaming *stream)
 	 * request on the probe control, as required by the UVC specification.
 	 */
 	ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
+
+	/*
+	 * Elgato Cam Link 4k can be in a stalled state if the resolution of
+	 * the external source has changed while the firmware initializes.
+	 * Once in this state, the device is useless until it receives a
+	 * USB reset. It has even been observed that the stalled state will
+	 * continue even after unplugging the device.
+	 */
+	if (ret == -EPROTO &&
+	    usb_match_one_id(stream->dev->intf, &elgato_cam_link_4k)) {
+		dev_err(&stream->intf->dev, "Elgato Cam Link 4K firmware crash detected\n");
+		dev_err(&stream->intf->dev, "Resetting the device, unplug and replug to recover\n");
+		usb_reset_device(stream->dev->udev);
+	}
+
 	if (ret < 0)
 		return ret;