September 2011 - kernelnewbies@kernelnewbies.org

Evicting Anonymous pages.
by Prateek Sharma Sept. 30, 2011

Sept. 30, 2011

Hello everyone, I am trying to understand the kernel page frame reclaiming mechanism, but one thing's bothering me: How does the kernel 'know' which anonymous pages to evict? In the LRU scheme, 'referenced/used' information for each page is required (AFAIK). But anonymous pages can be used by user processes 'at any time' without the kernel knowing about it. Am i missing something? Or does the kernel just drop some random anon pages of a process? Is there a way to obtain the 'referenced' information about anonymous pages as well? Thanks, Prateek

4 4

Kernel not showing in grub2
by scott Sept. 29, 2011

Sept. 29, 2011

I compiled a 3.0.0-rc7 kernel. Everything went smoothly except it doesn't show in the grub menu even after doing sudo update-grub. I see the kernel in /boot/grub/grub.cfg. Everything appears right with the UUID's and all. I noticed in /boot it doesn't list the abi-3.0-rc7. System-map initrd-img, vmlinux and config are all there. Would the missing abi- keep grub from recognizing it or am I barking up the wrong tree. If it is, how do I go about creating the abi short of recompiling. Thanks, Scott

3 5

Re: Kernel not showing in grub2
by scott Sept. 29, 2011

Sept. 29, 2011

On 09/28/2011 10:07 AM, Pritam Bankar wrote: > Check the /lib/modules directory for corresponding entry for 3.0.0. > sudo update-grub does only scanning of /boot directory and puts them in a > list so its look like grub update error. > abi-3.0-rc7 will not create because its only present when your kernel comes > from standard distro. > Anyway you can manually edit grub.cfg file. > > > On Wed, Sep 28, 2011 at 6:41 AM, scott<redhowlingwolves(a)nc.rr.com> wrote: > >> I compiled a 3.0.0-rc7 kernel. Everything went smoothly except it >> doesn't show in the grub menu even after doing sudo update-grub. I see >> the kernel in /boot/grub/grub.cfg. Everything appears right with the >> UUID's and all. I noticed in /boot it doesn't list the abi-3.0-rc7. >> System-map initrd-img, vmlinux and config are all there. >> >> Would the missing abi- keep grub from recognizing it or am I barking up >> the wrong tree. If it is, how do I go about creating the abi short of >> recompiling. >> >> Thanks, Scott >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies(a)kernelnewbies.org >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> > > >

1 0

Prevent a process from opening a file more than once
by Venkatram Tummala Sept. 28, 2011

Sept. 28, 2011

Hi All, I have a simple device driver which creates a /dev/XYZ file. I need to prevent a process from opening the file more than once. However, multiple processes can open the file simultaneously. Is there any any elegant way to do this other than checking all opened files in the process ?

6 11

Issue about setting interface flag on network device.
by 陳國成 Sept. 26, 2011

Sept. 26, 2011

Hi, I encounter a strange problem when using 2.6.30 kernel. There are two processes, one runs main1() and the other runs main2(). Two processes are running simultaneously on uni-processor system. Besides, eth0 is a proprietory ethernet driver. IFF_ALLMULTI can be set on eth0 successfully most of the time. The result looks like: main2: save_flags = 0x1043, flags = 0x1243 seldom, setting IFF_ALLMULTI on eth0 will not take effect and the result looks like: main2: save_flags = 0x1002, flags = 0x1043 main2: ret = 0 Please give me some suggestion about how to debug this issue. int ifUp(const char *ifName) { int sockfd = 0; struct ifreq ifr; int ret = 0; if (ifName == NULL) { ret = -1; } else { if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { ret = -1; } else { strncpy(ifr.ifr_name, ifName, IFNAMSIZ); ifr.ifr_flags = (IFF_UP | IFF_RUNNING | IFF_MULTICAST); if (ioctl(sockfd, SIOCSIFFLAGS, &ifr) < 0) { ret = -1; } close(sockfd); } } return ret; } short get_interface_flags(char *ifname) { struct ifreq ifr; int sockfd, err; sockfd = socket(PF_INET, SOCK_DGRAM, 0); if (sockfd <= 0) return -1; strncpy(ifr.ifr_name, ifname, IFNAMSIZ); err = ioctl(sockfd, SIOCGIFFLAGS, (void*)&ifr); close(sockfd); if (err != 0) return -1; return ifr.ifr_flags; } short set_interface_flags(char *ifname, short flags) { struct ifreq ifr; int sockfd, err; sockfd = socket(PF_INET, SOCK_DGRAM, 0); if (sockfd <= 0) return -1; strncpy(ifr.ifr_name, ifname, IFNAMSIZ); ifr.ifr_flags = flags; err = ioctl(sockfd, SIOCSIFFLAGS, (void*)&ifr); close(sockfd); if (err != 0) return -1; return 0; } int main1() { ifUp("eth0"); } int main2() { short flags, save_flags; short ret; /* Set the interface flags to receive all multicast packets */ save_flags = get_interface_flags("eth0"); if (save_flags != -1) { ret = set_interface_flags("eth0", save_flags | IFF_ALLMULTI); flags = get_interface_flags("eth0"); printf("%s: save_flags = 0x%x, flags = 0x%x\n", __FUNCTION__, save_flags, flags); if (((flags & IFF_ALLMULTI) != IFF_ALLMULTI)) { printf("%s: ret = %d\n", __FUNCTION__, ret); } } } Thanks & Regards, GC

2 1

Re: Fw: Automatic module insert in boot time
by Yacob Hassidim Sept. 26, 2011

Sept. 26, 2011

Hello Matt, Thank you for your answer. The driver is a simple one (hello) and does not require any hardware. Sincerely, Yacob Hassidim. ----- Original Message ----- From: "Matt Schulte" <matts(a)commtech-fastcom.com> To: "Yacob Hassidim" <yacobh(a)zahav.net.il> Sent: Monday, September 26, 2011 6:59 PM Subject: Re: Fw: Automatic module insert in boot time >I believe the reason it is not installing as you would like with the > automatic /etc/modules method is that it requires hardware to be > detected before it loads the driver. It will not automatically load > drivers unless it detects hardware that needs them. > > Matt Schulte > > On Mon, Sep 26, 2011 at 6:59 AM, Yacob Hassidim <yacobh(a)zahav.net.il> > wrote: >>> Hello Mulyadi, >>> >>> Thank you for your response. >>> >>> I read the best way to automatically insert a module is via the >>> /etc/modules (see >>> http://www.cyberciti.biz/faq/linux-how-to-load-a-kernel-module-automaticall…) >>> >>> Don't forget I use Ubuntu 11.04. >>> >>> I tried the rc.local: It works perfectly. >>> >>> I searched for initramfs file but didn't find at all under Ubuntu. >>> >>> Sincerely, >>> >>> Yacob Hassidim. >>> >>> >>> >>> ----- Original Message ----- >>> From: "Mulyadi Santosa" <mulyadi.santosa(a)gmail.com> >>> To: "Yacob Hassidim" <yacobh(a)zahav.net.il> >>> Cc: <kernelnewbies(a)kernelnewbies.org> >>> Sent: Monday, September 26, 2011 11:04 AM >>> Subject: Re: Automatic module insert in boot time >>> >>> >>>> Hi Yacob... >>>> >>>> 2011/9/26 Yacob Hassidim <yacobh(a)zahav.net.il>: >>>>> ________________________________ >>>>> Hello everyone, >>>>> >>>>> I ask for help to insert/install module automatically in boot time. >>>>> >>>>> I use Ubuntu 11.04. >>>>> >>>>> I try to insert a module automatically in boot time. >>>>> >>>>> I added the name of my module (hello) to the file /etc/modules. >>>> >>>> I don't think that is the place. >>>> >>>> Boot time? perhaps better to put your modprobe/insmod calling your >>>> module in something like rc.local, or manually modify your >>>> initrd/initramfs so that it load your module earlier. >>>> >>>> >>>> -- >>>> regards, >>>> >>>> Mulyadi Santosa >>>> Freelance Linux trainer and consultant

1 0

CPU pinning
by Kernel Piddu Sept. 26, 2011

Sept. 26, 2011

> I have a multi processor system/machine and I would like dedicate a CPU entirely to listen on to a port. > I would greatly appreciate if you could tell me how this can be done. > > Thanks!

2 3

Including library in the Linux open source
by Sahana B Adiga - ERS, HCL Tech Sept. 26, 2011

Sept. 26, 2011

Hi All, For a new storage hardware we have a Linux device driver that uses a custom library for hardware interface. This h/w interface library is an intellectual property. We want to share the Linux device driver source code, but not the library source code. 1) Is it possible to add to the Linux open source, such a driver along with the hardware interface library as a blob? Will the Linux kernel community accepts/approves it? 2) If so, what is the procedure involved? 3) Are there any additional documentation or any extra steps required than the normal way of submitting device drivers to Linux kernel community? Regards, Sahana ::DISCLAIMER:: ----------------------------------------------------------------------------------------------------------------------- The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. It shall not attach any liability on the originator or HCL or its affiliates. Any views or opinions presented in this email are solely those of the author and may not necessarily reflect the opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any mail and attachments please check them for viruses and defect. -----------------------------------------------------------------------------------------------------------------------

2 1

Fw: Automatic module insert in boot time
by Yacob Hassidim Sept. 26, 2011

Sept. 26, 2011

----- Original Message ----- From: "Yacob Hassidim" <yacobh(a)zahav.net.il> To: "Mulyadi Santosa" <mulyadi.santosa(a)gmail.com> Sent: Monday, September 26, 2011 2:51 PM Subject: Re: Automatic module insert in boot time > Hello Mulyadi, > > Thank you for your response. > > I read the best way to automatically insert a module is via the > /etc/modules (see > http://www.cyberciti.biz/faq/linux-how-to-load-a-kernel-module-automaticall…) > > Don't forget I use Ubuntu 11.04. > > I tried the rc.local: It works perfectly. > > I searched for initramfs file but didn't find at all under Ubuntu. > > Sincerely, > > Yacob Hassidim. > > > > ----- Original Message ----- > From: "Mulyadi Santosa" <mulyadi.santosa(a)gmail.com> > To: "Yacob Hassidim" <yacobh(a)zahav.net.il> > Cc: <kernelnewbies(a)kernelnewbies.org> > Sent: Monday, September 26, 2011 11:04 AM > Subject: Re: Automatic module insert in boot time > > >> Hi Yacob... >> >> 2011/9/26 Yacob Hassidim <yacobh(a)zahav.net.il>: >>> ________________________________ >>> Hello everyone, >>> >>> I ask for help to insert/install module automatically in boot time. >>> >>> I use Ubuntu 11.04. >>> >>> I try to insert a module automatically in boot time. >>> >>> I added the name of my module (hello) to the file /etc/modules. >> >> I don't think that is the place. >> >> Boot time? perhaps better to put your modprobe/insmod calling your >> module in something like rc.local, or manually modify your >> initrd/initramfs so that it load your module earlier. >> >> >> -- >> regards, >> >> Mulyadi Santosa >> Freelance Linux trainer and consultant >> >> blog: the-hydra.blogspot.com >> training: mulyaditraining.blogspot.com >

1 0

generic-usb: probe of 0003:074D:3576.0002 failed with error -22
by Stanislav Stratu Sept. 26, 2011

Sept. 26, 2011

Hello, I have some problems with a USB headset with PTT functionality on it, the audio works well, but not the PTT. I attached error messages from different kernels, also the device's description. The insertion receive error: generic-usb: probe of 0003:074D:3576.0002 failed with error -22 and the PTT, which is made with HID InterfaceClass not create any entry in /dev/input/ or /dev/hidraw * Does anyone know how to fix this? thanks in advance. on the Ubuntu-10.10 kernel 2.6.35-22-generic dmesg [ 67.104034] usb 2-1: new full speed USB device using uhci_hcd and address 3 [ 67.334528] generic-usb: probe of 0003:074D:3576.0003 failed with error -22 [ 67.497473] usbcore: registered new interface driver snd-usb-audio on the Ubuntu-10.10 custom realtime-kernel 3.0.3-rt12 dmesg usb 1-1: new full speed USB device number 4 using uhci_hcd usb 1-1: New USB device found, idVendor=074d, idProduct=3576 usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 1-1: Product: PTT Imtradex Headset usb 1-1: Manufacturer: Imtradex usb_audio: Warning! Unlikely big volume range (=656), cval->res is probably wrong. usb_audio: [6] FU [PCM Capture Volume] ch = 1, val = -10496/0/16 generic-usb: probe of 0003:074D:3576.0004 failed with error -22 lsusb -vd 074d:3576 Bus 001 Device 004: ID 074d:3576 Micronas GmbH Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 8 idVendor 0x074d Micronas GmbH idProduct 0x3576 bcdDevice 0.09 iManufacturer 1 Imtradex iProduct 2 PTT Imtradex Headset iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 415 bNumInterfaces 4 bConfigurationValue 1 iConfiguration 3 A0 2009/05/18 15:23 bmAttributes 0xc0 Self Powered MaxPower 256mA 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 10 bDescriptorType 36 bDescriptorSubtype 1 (HEADER) bcdADC 1.00 wTotalLength 124 bInCollection 2 baInterfaceNr( 0) 1 baInterfaceNr( 1) 2 AudioControl Interface Descriptor: bLength 12 bDescriptorType 36 bDescriptorSubtype 2 (INPUT_TERMINAL) bTerminalID 10 wTerminalType 0x0201 Microphone bAssocTerminal 0 bNrChannels 2 wChannelConfig 0x0003 Left Front (L) Right Front (R) iChannelNames 0 iTerminal 0 AudioControl Interface Descriptor: bLength 12 bDescriptorType 36 bDescriptorSubtype 2 (INPUT_TERMINAL) bTerminalID 11 wTerminalType 0x0603 Line Connector bAssocTerminal 0 bNrChannels 2 wChannelConfig 0x0003 Left Front (L) Right Front (R) iChannelNames 0 iTerminal 0 AudioControl Interface Descriptor: bLength 12 bDescriptorType 36 bDescriptorSubtype 2 (INPUT_TERMINAL) bTerminalID 12 wTerminalType 0x0101 USB Streaming bAssocTerminal 0 bNrChannels 2 wChannelConfig 0x0003 Left Front (L) Right Front (R) iChannelNames 0 iTerminal 0 AudioControl Interface Descriptor: bLength 13 bDescriptorType 36 bDescriptorSubtype 6 (FEATURE_UNIT) bUnitID 2 bSourceID 10 bControlSize 2 bmaControls( 0) 0x02 bmaControls( 0) 0x00 Volume bmaControls( 1) 0x00 bmaControls( 1) 0x00 bmaControls( 2) 0x00 bmaControls( 2) 0x00 iFeature 0 AudioControl Interface Descriptor: bLength 13 bDescriptorType 36 bDescriptorSubtype 6 (FEATURE_UNIT) bUnitID 3 bSourceID 11 bControlSize 2 bmaControls( 0) 0x02 bmaControls( 0) 0x00 Volume bmaControls( 1) 0x00 bmaControls( 1) 0x00 bmaControls( 2) 0x00 bmaControls( 2) 0x00 iFeature 0 AudioControl Interface Descriptor: bLength 13 bDescriptorType 36 bDescriptorSubtype 6 (FEATURE_UNIT) bUnitID 1 bSourceID 12 bControlSize 2 bmaControls( 0) 0x55 bmaControls( 0) 0x01 Mute Bass Treble Automatic Gain Bass Boost bmaControls( 1) 0x02 bmaControls( 1) 0x00 Volume bmaControls( 2) 0x02 bmaControls( 2) 0x00 Volume iFeature 0 AudioControl Interface Descriptor: bLength 9 bDescriptorType 36 bDescriptorSubtype 3 (OUTPUT_TERMINAL) bTerminalID 20 wTerminalType 0x0301 Speaker bAssocTerminal 0 bSourceID 1 iTerminal 0 AudioControl Interface Descriptor: bLength 8 bDescriptorType 36 bDescriptorSubtype 5 (SELECTOR_UNIT) bUnitID 8 bNrInPins 2 baSource( 0) 2 baSource( 1) 3 iSelector 0 AudioControl Interface Descriptor: bLength 13 bDescriptorType 36 bDescriptorSubtype 6 (FEATURE_UNIT) bUnitID 6 bSourceID 8 bControlSize 2 bmaControls( 0) 0x03 bmaControls( 0) 0x00 Mute Volume bmaControls( 1) 0x00 bmaControls( 1) 0x00 bmaControls( 2) 0x00 bmaControls( 2) 0x00 iFeature 0 AudioControl Interface Descriptor: bLength 9 bDescriptorType 36 bDescriptorSubtype 3 (OUTPUT_TERMINAL) bTerminalID 13 wTerminalType 0x0101 USB Streaming bAssocTerminal 0 bSourceID 6 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 12 bDelay 0 frames wFormatTag 1 PCM AudioStreaming Interface Descriptor: bLength 14 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bNrChannels 1 bSubframeSize 2 bBitResolution 16 bSamFreqType 0 Continuous tLowerSamFreq 6400 tUpperSamFreq 48000 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x01 EP 1 OUT bmAttributes 9 Transfer Type Isochronous Synch Type Adaptive Usage Type Data wMaxPacketSize 0x0064 1x 100 bytes bInterval 1 bRefresh 0 bSynchAddress 0 AudioControl Endpoint Descriptor: bLength 7 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x01 Sampling Frequency bLockDelayUnits 2 Decoded PCM samples wLockDelay 1 Decoded PCM samples Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 2 bNumEndpoints 1 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 0 iInterface 0 AudioStreaming Interface Descriptor: bLength 7 bDescriptorType 36 bDescriptorSubtype 1 (AS_GENERAL) bTerminalLink 12 bDelay 0 frames wFormatTag 1 PCM AudioStreaming Interface Descriptor: bLength 14 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bNrChannels 2 bSubframeSize 2 bBitResolution 16 bSamFreqType 0 Continuous tLowerSamFreq 6400 tUpperSamFreq 48000 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x01 EP 1 OUT bmAttributes 9 Transfer Type Isochronous Synch Type Adaptive Usage Type Data wMaxPacketSize 0x00c8 1x 200 bytes bInterval 1 bRefresh 0 bSynchAddress 0 AudioControl Endpoint Descriptor: bLength 7 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x01 Sampling Frequency bLockDelayUnits 2 Decoded PCM samples wLockDelay 1 Decoded PCM samples Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 0 iInterface 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 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 13 bDelay 0 frames wFormatTag 1 PCM AudioStreaming Interface Descriptor: bLength 14 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bNrChannels 1 bSubframeSize 1 bBitResolution 8 bSamFreqType 0 Continuous tLowerSamFreq 6400 tUpperSamFreq 48000 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 9 Transfer Type Isochronous Synch Type Adaptive Usage Type Data wMaxPacketSize 0x0032 1x 50 bytes bInterval 1 bRefresh 0 bSynchAddress 0 AudioControl Endpoint Descriptor: bLength 7 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x01 Sampling Frequency bLockDelayUnits 2 Decoded PCM samples wLockDelay 1 Decoded PCM samples Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 2 bNumEndpoints 1 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 0 iInterface 0 AudioStreaming Interface Descriptor: bLength 7 bDescriptorType 36 bDescriptorSubtype 1 (AS_GENERAL) bTerminalLink 13 bDelay 0 frames wFormatTag 1 PCM AudioStreaming Interface Descriptor: bLength 14 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bNrChannels 1 bSubframeSize 2 bBitResolution 16 bSamFreqType 0 Continuous tLowerSamFreq 6400 tUpperSamFreq 48000 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 9 Transfer Type Isochronous Synch Type Adaptive Usage Type Data wMaxPacketSize 0x0064 1x 100 bytes bInterval 1 bRefresh 0 bSynchAddress 0 AudioControl Endpoint Descriptor: bLength 7 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x01 Sampling Frequency bLockDelayUnits 2 Decoded PCM samples wLockDelay 1 Decoded PCM samples Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 3 bNumEndpoints 1 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 0 iInterface 0 AudioStreaming Interface Descriptor: bLength 7 bDescriptorType 36 bDescriptorSubtype 1 (AS_GENERAL) bTerminalLink 13 bDelay 0 frames wFormatTag 1 PCM AudioStreaming Interface Descriptor: bLength 14 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bNrChannels 2 bSubframeSize 2 bBitResolution 16 bSamFreqType 0 Continuous tLowerSamFreq 6400 tUpperSamFreq 48000 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 9 Transfer Type Isochronous Synch Type Adaptive Usage Type Data wMaxPacketSize 0x00c8 1x 200 bytes bInterval 1 bRefresh 0 bSynchAddress 0 AudioControl Endpoint Descriptor: bLength 7 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x01 Sampling Frequency bLockDelayUnits 2 Decoded PCM samples wLockDelay 1 Decoded PCM samples Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 3 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 0 No Subclass bInterfaceProtocol 0 None iInterface 4 PTT Headset Button HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.00 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 50 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 0x0002 1x 2 bytes bInterval 8 Device Status: 0x0000 (Bus Powered)

1 0