[PATCH v1 1/1] media: uvcvideo: Recover stalled ElGato devices

From: Ricardo Ribalda
Date: Tue Sep 20 2022 - 10:07:41 EST

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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
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x01ca
bNumInterfaces 5
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 800mA
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 0
bInterfaceCount 2
bFunctionClass 14 Video
bFunctionSubClass 3 Video Interface Collection
bFunctionProtocol 0
iFunction 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 1 Video Control
bInterfaceProtocol 0
iInterface 5 Cam Link 4K
VideoControl Interface Descriptor:
bLength 13
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdUVC 1.10
wTotalLength 0x002b
dwClockFrequency 0.000000MHz
bInCollection 1
baInterfaceNr( 0) 1
VideoControl Interface Descriptor:
bLength 8
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0200 Input Vendor Specific
bAssocTerminal 0
iTerminal 0
VideoControl Interface Descriptor:
bLength 13
bDescriptorType 36
bDescriptorSubtype 5 (PROCESSING_UNIT)
bUnitID 2
bSourceID 1
wMaxMultiplier 0
bControlSize 3
bmControls 0x0000000f
Brightness
Contrast
Hue
Saturation
iProcessing 0
bmVideoStandards 0x00
VideoControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 3
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 2
iTerminal 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
bMaxBurst 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 5 Cam Link 4K
VideoStreaming Interface Descriptor:
bLength 16
bDescriptorType 36
bDescriptorSubtype 1 (INPUT_HEADER)
bNumFormats 3
wTotalLength 0x00cd
bEndpointAddress 0x83 EP 3 IN
bmInfo 0
bTerminalLink 3
bStillCaptureMethod 1
bTriggerSupport 0
bTriggerUsage 0
bControlSize 1
bmaControls( 0) 0
bmaControls( 1) 0
bmaControls( 2) 0
VideoStreaming Interface Descriptor:
bLength 27
bDescriptorType 36
bDescriptorSubtype 4 (FORMAT_UNCOMPRESSED)
bFormatIndex 1
bNumFrameDescriptors 1
guidFormat {3231564e-0000-0010-8000-00aa00389b71}
bBitsPerPixel 12
bDefaultFrameIndex 1
bAspectRatioX 0
bAspectRatioY 0
bmInterlaceFlags 0x00
Interlaced stream or variable: No
Fields per frame: 2 fields
Field 1 first: No
Field pattern: Field 1 only
bCopyProtect 0
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 1
bmCapabilities 0x01
Still image supported
wWidth 3840
wHeight 2160
dwMinBitRate 2985984000
dwMaxBitRate 2985984000
dwMaxVideoFrameBufferSize 12441600
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 13 (COLORFORMAT)
bColorPrimaries 1 (BT.709,sRGB)
bTransferCharacteristics 1 (BT.709)
bMatrixCoefficients 1 (BT.709)
VideoStreaming Interface Descriptor:
bLength 27
bDescriptorType 36
bDescriptorSubtype 4 (FORMAT_UNCOMPRESSED)
bFormatIndex 2
bNumFrameDescriptors 1
guidFormat {3231564e-0000-0010-8000-00aa00389b71}
bBitsPerPixel 12
bDefaultFrameIndex 1
bAspectRatioX 0
bAspectRatioY 0
bmInterlaceFlags 0x00
Interlaced stream or variable: No
Fields per frame: 2 fields
Field 1 first: No
Field pattern: Field 1 only
bCopyProtect 0
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 1
bmCapabilities 0x01
Still image supported
wWidth 3840
wHeight 2160
dwMinBitRate 2985984000
dwMaxBitRate 2985984000
dwMaxVideoFrameBufferSize 12441600
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 13 (COLORFORMAT)
bColorPrimaries 1 (BT.709,sRGB)
bTransferCharacteristics 1 (BT.709)
bMatrixCoefficients 1 (BT.709)
VideoStreaming Interface Descriptor:
bLength 27
bDescriptorType 36
bDescriptorSubtype 4 (FORMAT_UNCOMPRESSED)
bFormatIndex 3
bNumFrameDescriptors 1
guidFormat {30323449-0000-0010-8000-00aa00389b71}
bBitsPerPixel 12
bDefaultFrameIndex 1
bAspectRatioX 0
bAspectRatioY 0
bmInterlaceFlags 0x00
Interlaced stream or variable: No
Fields per frame: 2 fields
Field 1 first: No
Field pattern: Field 1 only
bCopyProtect 0
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 1
bmCapabilities 0x01
Still image supported
wWidth 3840
wHeight 2160
dwMinBitRate 2985984000
dwMaxBitRate 2985984000
dwMaxVideoFrameBufferSize 12441600
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 13 (COLORFORMAT)
bColorPrimaries 1 (BT.709,sRGB)
bTransferCharacteristics 1 (BT.709)
bMatrixCoefficients 1 (BT.709)
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 15
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 2
bInterfaceCount 1
bFunctionClass 3 Human Interface Device
bFunctionSubClass 0
bFunctionProtocol 0
iFunction 5 Cam Link 4K
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.01
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 207
Report Descriptors:
** UNAVAILABLE **
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x86 EP 6 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 10
bMaxBurst 0
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 3
bInterfaceCount 2
bFunctionClass 1 Audio
bFunctionSubClass 2 Streaming
bFunctionProtocol 0
iFunction 6 Cam Link 4K
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 1 Control Device
bInterfaceProtocol 0
iInterface 6 Cam Link 4K
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 0x001e
bInCollection 1
baInterfaceNr(0) 4
AudioControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0602 Digital Audio Interface
bAssocTerminal 0
bNrChannels 2
wChannelConfig 0x0003
Left Front (L)
Right Front (R)
iChannelNames 0
iTerminal 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 2
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 1
iTerminal 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 4
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 6 Cam Link 4K
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 4
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 6 Cam Link 4K
AudioStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (AS_GENERAL)
bTerminalLink 2
bDelay 1 frames
wFormatTag 0x0001 PCM
AudioStreaming Interface Descriptor:
bLength 11
bDescriptorType 36
bDescriptorSubtype 2 (FORMAT_TYPE)
bFormatType 1 (FORMAT_TYPE_I)
bNrChannels 2
bSubframeSize 2
bBitResolution 16
bSamFreqType 1 Discrete
tSamFreq[ 0] 48000
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x00c0 1x 192 bytes
bInterval 4
bRefresh 0
bSynchAddress 0
bMaxBurst 0
AudioStreaming Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x00
bLockDelayUnits 0 Undefined
wLockDelay 0x0000
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 0x0016
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
HIRD Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 3
Lowest fully-functional device speed is SuperSpeed (5Gbps)
bU1DevExitLat 0 micro seconds
bU2DevExitLat 0 micro seconds
Device Status: 0x0000
(Bus Powered)

Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 170a008f4006..ad1762b66c4c 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -129,12 +129,12 @@ 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 +297,7 @@ 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 +2121,20 @@ 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 (usb_match_one_id(stream->dev->intf, &elgato_cam_link_4k) &&
+ (ret == -EPROTO)) {
+ usb_reset_device(stream->dev->udev);
+ dev_err(&stream->intf->dev, "Restarting Elgato Cam Link 4K\n");
+ }
+
if (ret < 0)
return ret;

--
b4 0.11.0-dev-d93f8

Next message: Paul Kocialkowski: "Re: [PATCH] media: i2c: ov5648: Free V4L2 fwnode data on unbind"
Previous message: Ricardo Ribalda: "[PATCH v1 0/1] [RESEND] Recover stalled ElGato devices"
In reply to: Ricardo Ribalda: "[PATCH v1 0/1] [RESEND] Recover stalled ElGato devices"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]