记录USB摄像头的几个问题

usb 1-1.2: device not accepting address 44, error -62

hub 1-1:1.0: unable to enumerate USB device on port 2

1.1 使用同一个usb摄像头，在电脑端可以输出：

<–the 0 image format information–>

description:YUYV 4:2:2

pixelformat:YUYV

discrete-framesize 0:640x480

discrete-framesize 1:800x600

discrete-framesize 2:1280x960

discrete-framesize 3:1600x1200

可以正常拍摄4种类型的照片，

但在开发板上却只有：

<–the 0 image format information–>

description:YUV 4:2:2 (YUYV)

pixelformat:YUYV

discrete-framesize 0:320x240

可以正常拍320*240，但摄像高像素会自动校正为320*240，

使用另一款摄像头，只有：

<–the 0 image format information–>

description:YUV 4:2:2 (YUYV)

pixelformat:YUYV

discrete-framesize 0:320x240

discrete-framesize 1:160x120

两种，但拍摄320x240会阻塞，如果使用非阻塞模式就超时退出，在电脑上却有：

description:YUYV 4:2:2

pixelformat:YUYV

discrete-framesize 0:640x480

discrete-framesize 1:352x288

discrete-framesize 2:320x240

discrete-framesize 3:176x144

discrete-framesize 4:160x120

，

后来检查发现是开发板上的USB host 是1.1的，虚拟机模拟去掉USB2.0的支持，也一样出现阻塞情况。但emun出来的分辨率却一样有多种，应该是模拟环境还是有差异吧。

这是在虚拟机上支持usb2.0 host时测试的摄像头dmesg:

[19140.761165] usb 2-1: new high-speed USB device number 6 using ehci_hcd
[19140.936202] usb 2-1: New USB device found, idVendor=0c45, idProduct=6340
[19140.936208] usb 2-1: New USB device strings: Mfr=2, Product=1, SerialNumber=0
[19140.936211] usb 2-1: Product: USB 2.0 Camera
[19140.936214] usb 2-1: Manufacturer: Sonix Technology Co., Ltd.
[19140.942108] uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:6340)
[19140.960841] input: USB 2.0 Camera as /devices/pci0000:00/0000:00:11.0/0000:02:03.0/usb2/2-1/2-1:1.0/input/input19
[19140.989601] 6:3:1: cannot get freq at ep 0x84

当虚拟机去掉2.0的支持时dmesg如下 ：

[29118.682694] ehci_hcd 0000:02:03.0: remove, state 4
[29118.682710] usb usb1: USB disconnect, device number 1
[29118.682713] usb 1-1: USB disconnect, device number 7
[29118.698928] ehci_hcd 0000:02:03.0: USB bus 1 deregistered
[29130.499683] usb 2-2.2: new high-speed USB device number 5 using uhci_hcd
[29130.644298] usb 2-2.2: New USB device found, idVendor=0c45, idProduct=6340
[29130.644304] usb 2-2.2: New USB device strings: Mfr=2, Product=1, SerialNumber=0
[29130.644307] usb 2-2.2: Product: USB 2.0 Camera
[29130.644310] usb 2-2.2: Manufacturer: Sonix Technology Co., Ltd.
[29130.652422] uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:6340)
[29130.671720] input: USB 2.0 Camera as /devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/2-2/2-2.2/2-2.2:1.0/input/input11
[29130.697580] 5:3:1: cannot get freq at ep 0x84
[29130.832372] 5:3:1: cannot get freq at ep 0x84
[29130.887303] 5:3:1: cannot get freq at ep 0x84

ehci_hcd被unregister了，下面来看在开发板上的测试，

这是在开发板上usb1.0 host上测试的摄像头dmesg:

hub 1-1:1.0: debounce: port 3: total 100ms stable 100ms status 0x100
hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0008
hub 1-1:1.0: port 3, status 0101, change 0001, 12 Mb/s
hub 1-1:1.0: debounce: port 3: total 100ms stable 100ms status 0x101
usb 1-1.3: new full-speed USB device number 66 using s3c2410-ohci
usb 1-1.3: skipped 1 descriptor after configuration
usb 1-1.3: skipped 5 descriptors after interface
usb 1-1.3: skipped 1 descriptor after endpoint
usb 1-1.3: skipped 5 descriptors after interface
usb 1-1.3: skipped 1 descriptor after endpoint
usb 1-1.3: skipped 4 descriptors after interface
usb 1-1.3: skipped 2 descriptors after interface
usb 1-1.3: skipped 1 descriptor after endpoint
usb 1-1.3: default language 0x0409
usb 1-1.3: udev 66, busnum 1, minor = 65
usb 1-1.3: New USB device found, idVendor=0c45, idProduct=6340
usb 1-1.3: New USB device strings: Mfr=2, Product=1, SerialNumber=0
usb 1-1.3: Product: USB 2.0 Camera
usb 1-1.3: Manufacturer: Sonix Technology Co., Ltd.
usb 1-1.3: usb_probe_device
usb 1-1.3: configuration #1 chosen from 1 choice
usb 1-1.3: adding 1-1.3:1.0 (config #1, interface 0)
uvcvideo 1-1.3:1.0: usb_probe_interface
uvcvideo 1-1.3:1.0: usb_probe_interface - got id
uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:6340)
input: USB 2.0 Camera as /devices/platform/s3c2410-ohci/usb1/1-1/1-1.3/1-1.3:1.0/input/input7
evbug: Connected device: input7 (USB 2.0 Camera at usb-s3c24xx-1.3/button)
usb 1-1.3: adding 1-1.3:1.1 (config #1, interface 1)
usb 1-1.3: adding 1-1.3:1.2 (config #1, interface 2)
snd-usb-audio 1-1.3:1.2: usb_probe_interface
snd-usb-audio 1-1.3:1.2: usb_probe_interface - got id
66:3:1: cannot get freq at ep 0x84
usb 1-1.3: adding 1-1.3:1.3 (config #1, interface 3)
hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0008

可以看到，一个用的是ehci和uhci，开发板使用ohci，2440上没有ehci，所以无法处理高速接口。

linux USB HOST之EHCI和OHCI