Subject: [PATCH] USB: EHCI: fix for leaking isochronous data

From: [email-masked] (Soeren Moch)
Date: Fri, 15 Mar 2013 01:00:04 +0100

On 14.03.2013 22:33, Alan Stern wrote:
> On Thu, 14 Mar 2013, Soeren Moch wrote:
>
>>> If the memory really is being leaked here in some sort of systematic
>>> way, we may be able to see it in your debugging output after a few
>>> seconds.
>>>
>>
>> OK, here are the first seconds of the log. But the buffer exhaustion
>> usually occurs after several hours of runtime...
>
> The log shows a 1-1 match between allocations and deallocations, except
> for three excess allocations about 45 lines before the end.  I have no
> idea what's up with those.  They may be an artifact arising from where
> you stopped copying the log data.
>
> There are as many as 400 iTDs being allocated before any are freed.
> That seems like a lot.  Are they all for the same isochronous endpoint?
> What's the endpoint's period?  How often are URBs submitted?

I use 2 dvb sticks, capturing digital TV. For each stick 5 URBs on a 
single endpoint are used, I think. I'm not sure, which endpoint in which 
alternateSetting is active. I attached the output of 'lsusb -v' for the 
sticks.
How can I track down the other information you need?

> In general, there shouldn't be more than a couple of millisecond's
> worth of iTDs allocated for any endpoint, depending on how many URBs
> are in the pipeline at any time.

Maybe the em28xx driver is not doing a good job here!?

  Soeren Moch

> Maybe a better way to go about this is, instead of printing out every
> allocation and deallocation, to keep a running counter.  You could have
> the driver print out the value of this counter every minute or so.  Any
> time the device isn't in use, the counter should be 0.
>
> Alan Stern

Bus 001 Device 005: ID 0ccd:00b2 TerraTec Electronic GmbH
Device Descriptor:
   bLength                18
   bDescriptorType         1
   bcdUSB               2.00
   bDeviceClass            0 (Defined at Interface level)
   bDeviceSubClass         0
   bDeviceProtocol         0
   bMaxPacketSize0        64
   idVendor           0x0ccd TerraTec Electronic GmbH
   idProduct          0x00b2
   bcdDevice            1.00
   iManufacturer           3 TERRATEC
   iProduct                1 Cinergy HTC Stick
   iSerial                 2 123456789ABCD
   bNumConfigurations      1
   Configuration Descriptor:
     bLength                 9
     bDescriptorType         2
     wTotalLength          305
     bNumInterfaces          1
     bConfigurationValue     1
     iConfiguration          0
     bmAttributes         0x80
       (Bus Powered)
     MaxPower              500mA
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       0
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0000  1x 0 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0000  1x 0 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0000  1x 0 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       1
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0000  1x 0 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       2
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0ad0  2x 720 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       3
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0c00  2x 1024 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       4
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x1300  3x 768 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       5
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x1380  3x 896 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       6
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x13c0  3x 960 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       7
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x1400  3x 1024 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
Device Qualifier (for other device speed):
   bLength                10
   bDescriptorType         6
   bcdUSB               2.00
   bDeviceClass            0 (Defined at Interface level)
   bDeviceSubClass         0
   bDeviceProtocol         0
   bMaxPacketSize0        64
   bNumConfigurations      1
Device Status:     0x0000
   (Bus Powered)

Bus 001 Device 006: ID 2304:0242 Pinnacle Systems, Inc.
Device Descriptor:
   bLength                18
   bDescriptorType         1
   bcdUSB               2.00
   bDeviceClass            0 (Defined at Interface level)
   bDeviceSubClass         0
   bDeviceProtocol         0
   bMaxPacketSize0        64
   idVendor           0x2304 Pinnacle Systems, Inc.
   idProduct          0x0242
   bcdDevice            1.00
   iManufacturer           1 Pinnacle Systems
   iProduct                2 PCTV 510e
   iSerial                 3 123456789012
   bNumConfigurations      1
   Configuration Descriptor:
     bLength                 9
     bDescriptorType         2
     wTotalLength          305
     bNumInterfaces          1
     bConfigurationValue     1
     iConfiguration          0
     bmAttributes         0x80
       (Bus Powered)
     MaxPower              500mA
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       0
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0000  1x 0 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0000  1x 0 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0000  1x 0 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       1
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0000  1x 0 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       2
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0ad0  2x 720 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       3
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0c00  2x 1024 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       4
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x1300  3x 768 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       5
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x1380  3x 896 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       6
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x13c0  3x 960 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       7
       bNumEndpoints           4
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass      0
       bInterfaceProtocol    255
       iInterface              0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              11
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x82  EP 2 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x1400  3x 1024 bytes
         bInterval               1
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x00c4  1x 196 bytes
         bInterval               4
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x84  EP 4 IN
         bmAttributes            1
           Transfer Type            Isochronous
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x03ac  1x 940 bytes
         bInterval               1
Device Qualifier (for other device speed):
   bLength                10
   bDescriptorType         6
   bcdUSB               2.00
   bDeviceClass            0 (Defined at Interface level)
   bDeviceSubClass         0
   bDeviceProtocol         0
   bMaxPacketSize0        64
   bNumConfigurations      1
Device Status:     0x0000
   (Bus Powered)