* Re: bandwidth issue with usb-audio in alsa
@ 2008-05-27 13:10 Kunal Singh
2008-05-27 15:34 ` Clemens Ladisch
2008-05-27 15:47 ` Jon Smirl
0 siblings, 2 replies; 6+ messages in thread
From: Kunal Singh @ 2008-05-27 13:10 UTC (permalink / raw)
To: alsa-devel
Hi,
I have some update on the issue which I had reported earlier. In my last e-mail, I had not mentioned that iPod is connected to the target through a USB (HS) Hub. When I connect the
same hub to my Desktop and read its configuration using "usbview" - I see that "interval" for this hub is mentioned
as "256 msec". (I have two hubs and I get all the results same with both the hubs).
With 36 URBs, the gap between two set of transactions is appx 220 msec (220+36 => 256). So, I am wondering
if the problem which I am seeing is because the external hub. I can not connect iPod directly to my target board,
because this board does not support enough current (as needed by iPod).
Can some one suggest, where is the problem - is it with the host controller driver?
Regards,
Kunal Singh
-----------------------------
Kunal Singh wrote:
Hi,
My Platform
-------------
I am trying to stream audio data from a USB-device (an iPod) to my
arm-based embedded device (running kernel 2.6.23). The USB-device confirms
to usb digital audio (subclass - streaming) class. The endpoint buffer size
196 bytes and transfer period is 1 msec. So, I should be reading data every
msec.
Problem
-----------
I am facing some bandwidth issues. The data is not being captured fast
enough.
I notice that once one set of URBs are captured (one set equal to
MAX_URBS), there is a significant delay in capturing the next set of URBs.
I have set MAX_URBS equal to 32.
When I connect a USB-Analyzer and analyze the timings, I can see that
32 URBs are captured at a interval of 1 msec each. After that there is a
break of around 250 msec. And then again 32 URBs captured in sequence.
If I change the MAX_URBs to any other value N, N URBs get captured at
interval of 1 msec each, and then there is a break.
Can some one suggest a way to improve this problem. Is there some
configuration or parameter which I can change, so that URBs get submitted
fast enough? May be as soon as the old one has retired.
Thanks and Regards,
Kunal
www.singhkunal.com
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: bandwidth issue with usb-audio in alsa
2008-05-27 13:10 bandwidth issue with usb-audio in alsa Kunal Singh
@ 2008-05-27 15:34 ` Clemens Ladisch
2008-05-27 15:47 ` Jon Smirl
1 sibling, 0 replies; 6+ messages in thread
From: Clemens Ladisch @ 2008-05-27 15:34 UTC (permalink / raw)
To: Kunal Singh; +Cc: alsa-devel
Kunal Singh wrote:
> I have some update on the issue which I had reported earlier. In my last e-mail, I had not mentioned that iPod is connected to the target through a USB (HS) Hub. When I connect the
> same hub to my Desktop and read its configuration using "usbview" - I see that "interval" for this hub is mentioned
> as "256 msec". (I have two hubs and I get all the results same with both the hubs).
Please show the output of "lsusb -v".
Regards,
Clemens
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: bandwidth issue with usb-audio in alsa
2008-05-27 13:10 bandwidth issue with usb-audio in alsa Kunal Singh
2008-05-27 15:34 ` Clemens Ladisch
@ 2008-05-27 15:47 ` Jon Smirl
1 sibling, 0 replies; 6+ messages in thread
From: Jon Smirl @ 2008-05-27 15:47 UTC (permalink / raw)
To: Kunal Singh; +Cc: alsa-devel
On 5/27/08, Kunal Singh <kunal@singhkunal.com> wrote:
> Hi,
>
> I have some update on the issue which I had reported earlier. In my last e-mail, I had not mentioned that iPod is connected to the target through a USB (HS) Hub. When I connect the
> same hub to my Desktop and read its configuration using "usbview" - I see that "interval" for this hub is mentioned
> as "256 msec". (I have two hubs and I get all the results same with both the hubs).
>
> With 36 URBs, the gap between two set of transactions is appx 220 msec (220+36 => 256). So, I am wondering
> if the problem which I am seeing is because the external hub. I can not connect iPod directly to my target board,
> because this board does not support enough current (as needed by iPod).
Some USB 2.0 hubs are single TT (transaction translator). If the hub
is single TT all low speed USB devices share that TT. The pause could
be caused by other things using the TT.
USB audio, keyboards, older devices, all USB 1.0 all use the TT.
Single vs multi-TT is the source of a most USB audio problems. Get a
USB 2.0 hub that supports multi-TT. Of course the vendors don't
specify on the box single or multi-TT. Search on the web or email
their support group.
> Can some one suggest, where is the problem - is it with the host controller driver?
>
> Regards,
> Kunal Singh
>
> -----------------------------
>
>
> Kunal Singh wrote:
>
> Hi,
>
> My Platform
> -------------
> I am trying to stream audio data from a USB-device (an iPod) to my
> arm-based embedded device (running kernel 2.6.23). The USB-device confirms
> to usb digital audio (subclass - streaming) class. The endpoint buffer size
> 196 bytes and transfer period is 1 msec. So, I should be reading data every
> msec.
>
> Problem
> -----------
> I am facing some bandwidth issues. The data is not being captured fast
> enough.
>
> I notice that once one set of URBs are captured (one set equal to
> MAX_URBS), there is a significant delay in capturing the next set of URBs.
>
> I have set MAX_URBS equal to 32.
> When I connect a USB-Analyzer and analyze the timings, I can see that
> 32 URBs are captured at a interval of 1 msec each. After that there is a
> break of around 250 msec. And then again 32 URBs captured in sequence.
>
> If I change the MAX_URBs to any other value N, N URBs get captured at
> interval of 1 msec each, and then there is a break.
>
> Can some one suggest a way to improve this problem. Is there some
> configuration or parameter which I can change, so that URBs get submitted
> fast enough? May be as soon as the old one has retired.
>
> Thanks and Regards,
> Kunal
> www.singhkunal.com
>
>
>
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>
--
Jon Smirl
jonsmirl@gmail.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: bandwidth issue with usb-audio in alsa
@ 2008-05-28 5:12 kunal
0 siblings, 0 replies; 6+ messages in thread
From: kunal @ 2008-05-28 5:12 UTC (permalink / raw)
To: clemens, jonsmirl, alsa-devel
Hi Clemens/Jon,
I tried to understand the "lsusb -v" and started scanning through it.
After a few scan I realized that Bus-001 where I have connected my device
is a FS bus. The Bus-002 is HS. So, I moved my device to Bus-002. It all
works without any Bandwidth issues.
Thanks a lot for guiding me in to the right direction.
Can some one also suggest, why is there a problem with oss-emulation on
my system. I am using OSS-emulation API. As I mentioned earlier, I have a
sound card "card0" on my system which is mapped to /dev/dsp and I am able
to playback any data on this. As soon as I connect a USB-Audio device
(which reflects as Card1 in /proc/asound and new nodes /dev/dsp1
/dev/mixer1 etc created), I can no longer use the Card0. The /dev/dsp tries
to open a USB-Audio type devices (which should actually happen when I try
to open the /dev/dsp1). I think there is some dynamic remapping which
happens, and I am unable to trace it.
Regards,
Kunal
....
Hi Clemens,
I have copied the "lsusb -v" output below (end of this e-mail). The
"HUB" and the "iPod" are connected to Bus-001. Bus-002 is not being used.
As I can see from the Log, BUS-001 and BUS-002 both have usb (root ?)
hubs with single TT. Each of these buses have only one port available. So,
I guess that single "TT" should not be a problem. Am I right?
The Belking hub which I have connected to "Bus-001" has "TT" per
port. It also says "bInterval" equal to 255.
The iPod device which I am using has two configurations. I am using
the second configuration. Second configuration again has two interfaces.
Second (HID Class) interface is being used and works fine. Problem is with
the the first interface (with altsetting==1), which is an
audio-streaming-class.
The parameters for this interface are: (copied from the log below)
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x00c0 1x 192 bytes
bInterval 1
bRefresh 0
bSynchAddress 0
AudioControl Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 0 Undefined
wLockDelay 0 Undefined
Here "bInterval" is "1" and the transactions are not getting
scheduled at this desired speed.
Regards,
Kunal
Bus 002 Device 001: ID 0000:0000
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 1 Single TT
bMaxPacketSize0 64
idVendor 0x0000
idProduct 0x0000
bcdDevice 2.06
iManufacturer 3 Linux 2.6.22.6 ehci_hcd
iProduct 2 Freescale On-Chip EHCI Host Controller
iSerial 1 fsl-ehci.1
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 25
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 0mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
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 0x0004 1x 4 bytes
bInterval 12
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 1
wHubCharacteristic 0x0009
Per-port power switching
Per-port overcurrent protection
TT think time 8 FS bits
bPwrOn2PwrGood 10 * 2 milli seconds
bHubContrCurrent 0 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0x00
Hub Port Status:
Port 1: 0000.0100 power
Bus 001 Device 008: ID 05ac:1262 Apple Computer, Inc.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x05ac Apple Computer, Inc.
idProduct 0x1262
bcdDevice 0.01
iManufacturer 1 Apple Inc.
iProduct 2 iPod
iSerial 3 000A27001A2E8B0C
bNumConfigurations 2
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk (Zip)
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 149
bNumInterfaces 3
bConfigurationValue 2
iConfiguration 4 iPod USB Interface
bmAttributes 0xc0
Self Powered
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 1 Control Device
bInterfaceProtocol 0
iInterface 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 30
bInCollection 1
baInterfaceNr( 0) 1
AudioControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0201 Microphone
bAssocTerminal 2
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 1
bSourceID 1
iTerminal 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
AudioStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (AS_GENERAL)
bTerminalLink 2
bDelay 1 frames
wFormatTag 1 PCM
AudioStreaming Interface Descriptor:
bLength 35
bDescriptorType 36
bDescriptorSubtype 2 (FORMAT_TYPE)
bFormatType 1 (FORMAT_TYPE_I)
bNrChannels 2
bSubframeSize 2
bBitResolution 16
bSamFreqType 9 Discrete
tSamFreq[ 0] 8000
tSamFreq[ 1] 11025
tSamFreq[ 2] 12000
tSamFreq[ 3] 16000
tSamFreq[ 4] 22050
tSamFreq[ 5] 24000
tSamFreq[ 6] 32000
tSamFreq[ 7] 44100
tSamFreq[ 8] 48000
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x00c0 1x 192 bytes
bInterval 1
bRefresh 0
bSynchAddress 0
AudioControl Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 0 Undefined
wLockDelay 0 Undefined
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Devices
bInterfaceSubClass 0 No Subclass
bInterfaceProtocol 0 None
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.01
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 96
Report Descriptors:
** UNAVAILABLE **
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 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 2
Bus 001 Device 006: ID 050d:0234 Belkin Components F5U234 USB 2.0 4-Port Hub
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x050d Belkin Components
idProduct 0x0234 F5U234 USB 2.0 4-Port Hub
bcdDevice 0.00
iManufacturer 0
iProduct 0
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 25
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
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 255
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 4
wHubCharacteristic 0x0000
Ganged power switching
Ganged overcurrent protection
bPwrOn2PwrGood 50 * 2 milli seconds
bHubContrCurrent 1 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0x00
Hub Port Status:
Port 1: 0000.0103 power enable connect
Port 2: 0000.0100 power
Port 3: 0000.0100 power
Port 4: 0000.0100 power
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 2 TT per port
bMaxPacketSize0 64
bNumConfigurations 1
Bus 001 Device 001: ID 0000:0000
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 1 Single TT
bMaxPacketSize0 64
idVendor 0x0000
idProduct 0x0000
bcdDevice 2.06
iManufacturer 3 Linux 2.6.22.6 ehci_hcd
iProduct 2 Freescale On-Chip EHCI Host Controller
iSerial 1 fsl-ehci.0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 25
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 0mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
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 0x0004 1x 4 bytes
bInterval 12
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 1
wHubCharacteristic 0x0009
Per-port power switching
Per-port overcurrent protection
TT think time 8 FS bits
bPwrOn2PwrGood 10 * 2 milli seconds
bHubContrCurrent 0 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0x00
Hub Port Status:
Port 1: 0000.0103 power enable connect
Clemens Ladisch wrote:
> Kunal Singh wrote:
>
>> I have some update on the issue which I had reported earlier. In my
last e-mail, I had not mentioned that iPod is connected to the target
through a USB (HS) Hub. When I connect the
>> same hub to my Desktop and read its configuration using "usbview" - I
see that "interval" for this hub is mentioned
>> as "256 msec". (I have two hubs and I get all the results same with both
the hubs).
>>
>
> Please show the output of "lsusb -v".
>
>
> Regards,
> Clemens
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: bandwidth issue with usb-audio in alsa
@ 2008-05-28 3:03 kunal
0 siblings, 0 replies; 6+ messages in thread
From: kunal @ 2008-05-28 3:03 UTC (permalink / raw)
To: alsa-devel, clemens, jonsmirl
Hi Clemens,
I have copied the "lsusb -v" output below (end of this e-mail). The
"HUB" and the "iPod" are connected to Bus-001. Bus-002 is not being used.
As I can see from the Log, BUS-001 and BUS-002 both have usb (root ?)
hubs with single TT. Each of these buses have only one port available. So,
I guess that single "TT" should not be a problem. Am I right?
The Belking hub which I have connected to "Bus-001" has "TT" per
port. It also says "bInterval" equal to 255.
The iPod device which I am using has two configurations. I am using
the second configuration. Second configuration again has two interfaces.
Second (HID Class) interface is being used and works fine. Problem is with
the the first interface (with altsetting==1), which is an
audio-streaming-class.
The parameters for this interface are: (copied from the log below)
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x00c0 1x 192 bytes
bInterval 1
bRefresh 0
bSynchAddress 0
AudioControl Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 0 Undefined
wLockDelay 0 Undefined
Here "bInterval" is "1" and the transactions are not getting
scheduled at this desired speed.
Regards,
Kunal
Bus 002 Device 001: ID 0000:0000
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 1 Single TT
bMaxPacketSize0 64
idVendor 0x0000
idProduct 0x0000
bcdDevice 2.06
iManufacturer 3 Linux 2.6.22.6 ehci_hcd
iProduct 2 Freescale On-Chip EHCI Host Controller
iSerial 1 fsl-ehci.1
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 25
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 0mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
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 0x0004 1x 4 bytes
bInterval 12
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 1
wHubCharacteristic 0x0009
Per-port power switching
Per-port overcurrent protection
TT think time 8 FS bits
bPwrOn2PwrGood 10 * 2 milli seconds
bHubContrCurrent 0 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0x00
Hub Port Status:
Port 1: 0000.0100 power
Bus 001 Device 008: ID 05ac:1262 Apple Computer, Inc.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x05ac Apple Computer, Inc.
idProduct 0x1262
bcdDevice 0.01
iManufacturer 1 Apple Inc.
iProduct 2 iPod
iSerial 3 000A27001A2E8B0C
bNumConfigurations 2
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk (Zip)
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 149
bNumInterfaces 3
bConfigurationValue 2
iConfiguration 4 iPod USB Interface
bmAttributes 0xc0
Self Powered
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 1 Control Device
bInterfaceProtocol 0
iInterface 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 30
bInCollection 1
baInterfaceNr( 0) 1
AudioControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0201 Microphone
bAssocTerminal 2
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 1
bSourceID 1
iTerminal 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
AudioStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (AS_GENERAL)
bTerminalLink 2
bDelay 1 frames
wFormatTag 1 PCM
AudioStreaming Interface Descriptor:
bLength 35
bDescriptorType 36
bDescriptorSubtype 2 (FORMAT_TYPE)
bFormatType 1 (FORMAT_TYPE_I)
bNrChannels 2
bSubframeSize 2
bBitResolution 16
bSamFreqType 9 Discrete
tSamFreq[ 0] 8000
tSamFreq[ 1] 11025
tSamFreq[ 2] 12000
tSamFreq[ 3] 16000
tSamFreq[ 4] 22050
tSamFreq[ 5] 24000
tSamFreq[ 6] 32000
tSamFreq[ 7] 44100
tSamFreq[ 8] 48000
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x00c0 1x 192 bytes
bInterval 1
bRefresh 0
bSynchAddress 0
AudioControl Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 0 Undefined
wLockDelay 0 Undefined
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Devices
bInterfaceSubClass 0 No Subclass
bInterfaceProtocol 0 None
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.01
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 96
Report Descriptors:
** UNAVAILABLE **
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 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 2
Bus 001 Device 006: ID 050d:0234 Belkin Components F5U234 USB 2.0 4-Port Hub
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x050d Belkin Components
idProduct 0x0234 F5U234 USB 2.0 4-Port Hub
bcdDevice 0.00
iManufacturer 0
iProduct 0
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 25
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
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 255
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 4
wHubCharacteristic 0x0000
Ganged power switching
Ganged overcurrent protection
bPwrOn2PwrGood 50 * 2 milli seconds
bHubContrCurrent 1 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0x00
Hub Port Status:
Port 1: 0000.0103 power enable connect
Port 2: 0000.0100 power
Port 3: 0000.0100 power
Port 4: 0000.0100 power
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 2 TT per port
bMaxPacketSize0 64
bNumConfigurations 1
Bus 001 Device 001: ID 0000:0000
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 1 Single TT
bMaxPacketSize0 64
idVendor 0x0000
idProduct 0x0000
bcdDevice 2.06
iManufacturer 3 Linux 2.6.22.6 ehci_hcd
iProduct 2 Freescale On-Chip EHCI Host Controller
iSerial 1 fsl-ehci.0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 25
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 0mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
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 0x0004 1x 4 bytes
bInterval 12
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 1
wHubCharacteristic 0x0009
Per-port power switching
Per-port overcurrent protection
TT think time 8 FS bits
bPwrOn2PwrGood 10 * 2 milli seconds
bHubContrCurrent 0 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0x00
Hub Port Status:
Port 1: 0000.0103 power enable connect
Clemens Ladisch wrote:
> Kunal Singh wrote:
>
>> I have some update on the issue which I had reported earlier. In my
last e-mail, I had not mentioned that iPod is connected to the target
through a USB (HS) Hub. When I connect the
>> same hub to my Desktop and read its configuration using "usbview" - I
see that "interval" for this hub is mentioned
>> as "256 msec". (I have two hubs and I get all the results same with both
the hubs).
>>
>
> Please show the output of "lsusb -v".
>
>
> Regards,
> Clemens
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^ permalink raw reply [flat|nested] 6+ messages in thread* bandwidth issue with usb-audio in alsa
@ 2008-05-27 4:23 kunal
0 siblings, 0 replies; 6+ messages in thread
From: kunal @ 2008-05-27 4:23 UTC (permalink / raw)
To: alsa-devel
Hi,
My Platform
-------------
I am trying to stream audio data from a USB-device (an iPod) to my
arm-based embedded device (running kernel 2.6.23). The USB-device confirms
to usb digital audio (subclass - streaming) class. The endpoint buffer size
196 bytes and transfer period is 1 msec. So, I should be reading data every
msec.
Problem
-----------
I am facing some bandwidth issues. The data is not being captured fast
enough.
I notice that once one set of URBs are captured (one set equal to
MAX_URBS), there is a significant delay in capturing the next set of URBs.
I have set MAX_URBS equal to 32.
When I connect a USB-Analyzer and analyze the timings, I can see that
32 URBs are captured at a interval of 1 msec each. After that there is a
break of around 250 msec. And then again 32 URBs captured in sequence.
If I change the MAX_URBs to any other value N, N URBs get captured at
interval of 1 msec each, and then there is a break.
Can some one suggest a way to improve this problem. Is there some
configuration or parameter which I can change, so that URBs get submitted
fast enough? May be as soon as the old one has retired.
Thanks and Regards,
Kunal
www.singhkunal.com
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^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2008-05-28 5:12 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-05-27 13:10 bandwidth issue with usb-audio in alsa Kunal Singh
2008-05-27 15:34 ` Clemens Ladisch
2008-05-27 15:47 ` Jon Smirl
-- strict thread matches above, loose matches on Subject: below --
2008-05-28 5:12 kunal
2008-05-28 3:03 kunal
2008-05-27 4:23 kunal
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