linux-kernel - Re: [PATCH v4] media: uvcvideo: Recover stalled ElGato devices

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Date:   Thu, 29 Dec 2022 04:16:01 +0200
From:   Laurent Pinchart <laurent.pinchart@...asonboard.com>
To:     Ricardo Ribalda <ribalda@...omium.org>
Cc:     Mauro Carvalho Chehab <mchehab@...nel.org>,
        linux-media@...r.kernel.org,
        Sergey Senozhatsky <senozhatsky@...omium.org>,
        linux-kernel@...r.kernel.org, Yunke Cao <yunkec@...omium.org>
Subject: Re: [PATCH v4] media: uvcvideo: Recover stalled ElGato devices

Hi Ricardo,

On Tue, Dec 06, 2022 at 12:15:04AM +0100, Ricardo Ribalda wrote:
> 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.
> 
> lsusb -v
> 
> Bus 002 Device 002: ID 0fd9:0066 Elgato Systems GmbH Cam Link 4K
> Device Descriptor:
>   bLength                18
>   bDescriptorType         1
>   bcdUSB               3.00
>   bDeviceClass          239 Miscellaneous Device
>   bDeviceSubClass         2
>   bDeviceProtocol         1 Interface Association
>   bMaxPacketSize0         9
>   idVendor           0x0fd9 Elgato Systems GmbH
>   idProduct          0x0066
>   bcdDevice            0.00
>   iManufacturer           1 Elgato
>   iProduct                2 Cam Link 4K
>   iSerial                 4 0005AC52FE000
>   bNumConfigurations      1
> 
> Reviewed-by: Sergey Senozhatsky <senozhatsky@...omium.org>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>
> Signed-off-by: Ricardo Ribalda <ribalda@...omium.org>
> ---
> Recover stalled ElGato devices
> 
> Just a resend of this hw fix.

Taken in my tree, thanks.

> To: Laurent Pinchart <laurent.pinchart@...asonboard.com>
> To: Mauro Carvalho Chehab <mchehab@...nel.org>
> Cc: linux-media@...r.kernel.org
> Cc: linux-kernel@...r.kernel.org
> Cc: Sergey Senozhatsky <senozhatsky@...omium.org>
> Cc: Yunke Cao <yunkec@...omium.org>
> ---
> Changes in v4:
> - Add Reviewed-by: Laurent
> - Update error messages (Thanks Laurent!)
> - Swap checks on if (Thanks Laurent)
> - Link to v3: https://lore.kernel.org/r/20220920-resend-elgato-v3-0-57668054127f@chromium.org
> 
> Changes in v3:
> - Add Reviewed-by: Sergey
> - Improve identation (Thanks Sergey!)
> - Link to v2: https://lore.kernel.org/r/20220920-resend-elgato-v2-0-06b48b3b486a@chromium.org
> 
> Changes in v2:
> - Remove info from lsusb 
> - Link to v1: https://lore.kernel.org/r/20220920-resend-elgato-v1-0-8672a2380e3d@chromium.org
> ---
>  drivers/media/usb/uvc/uvc_video.c | 24 ++++++++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index 170a008f4006..ba7c159cb2a6 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -129,12 +129,13 @@ 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 +298,7 @@ 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;
>  	}
>  
> @@ -2121,6 +2122,21 @@ 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;
>  
> 
> ---
> base-commit: 521a547ced6477c54b4b0cc206000406c221b4d6
> change-id: 20220920-resend-elgato-a845482bdd02

-- 
Regards,

Laurent Pinchart