USB Gadget 模拟摄像头 g_webcam: musb-hdrc.4.auto: failed to start g_webcam: -22

wuhanstudio LV 3

大家好，

最近想用 OrangePi One (H3) 做一个虚拟摄像头，在开发板上读取原始摄像头的图像，做一些图像处理，再虚拟一个摄像头发到电脑上。

image.png.557a4c0d86464d5f6e63abe62151908a.png

我参考的这个树莓派的项目：

https://github.com/likeablob/rpi-wfh-webcam

在树莓派上 modprobe g_webcam 可以正常加载，但是在好几块 H3 的板子上 (运行的 Armbian) 都报同样的错误：

$ sudo modprobe g_webcam 
musb-hdrc.4.auto: failed to start g_webcam: -22

于是我又尝试了更新的 configfs，但是依旧是同样的错误：

https://developer.ridgerun.com/wiki/index.php?title=How_to_use_the_UVC_gadget_driver_in_Linux

sudo modprobe libcomposite dwc2 usb_f_uvc

mkdir -p /sys/kernel/config/usb_gadget/g1
cd /sys/kernel/config/usb_gadget/g1
echo 0x0525 > idVendor
echo 0x0102 > idProduct

mkdir -p strings/0x409
echo 0123456789 > strings/0x409/serialnumber
echo $(hostname) > strings/0x409/manufacturer
echo "UVC Gadget" > strings/0x409/product

mkdir configs/c.1
mkdir configs/c.1/strings/0x409

mkdir functions/uvc.0
mkdir -p functions/uvc.0/streaming/uncompressed/u/360p

cat <<EOF > functions/uvc.0/streaming/uncompressed/u/360p/dwFrameInterval
666666
1000000
5000000
EOF

mkdir functions/uvc.0/streaming/header/h
cd functions/uvc.0/streaming/header/h
ln -s ../../uncompressed/u
cd ../../class/fs
ln -s ../../header/h
cd ../../class/hs
ln -s ../../header/h
cd ../../class/ss
ln -s ../../header/h
cd ../../../control
mkdir -p header/h
ln -s header/h class/fs
ln -s header/h class/ss
cd ../../../

echo 2048 > functions/uvc.0/streaming_maxpacket
ln -s functions/uvc.0 configs/c.1

ls /sys/class/udc > UDC

不过 g_serial 和 g_eth 都能正常工作，请问是不是 H3 的芯片本身 USB IP 核不支持模拟摄像头呢？

memory LV 7

据说是端点(end point)不够。

wuhanstudio LV 3

@memory 多谢提醒，于是我对比了一下3个芯片的手册：

Allwinner H3:
https://wiki.friendlyarm.com/wiki/images/4/4b/Allwinner_H3_Datasheet_V1.2.pdf

Raspberrypi Zero (BCM2835):
https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf

Allwinner D1:
https://dl.linux-sunxi.org/D1/D1_Datasheet_V0.1_Draft_Version.pdf

H3 和 BCM2835 的 User-Configurable Endpoint 数量都是 8，D1 数量是 10，测试结果 H3 不能用 g_webcam，BCM2835 和 D1s 可以用。

我也感觉不是 linux 固件的问题，而是 H3 芯片本身不支持，但不完全确定是 Endpoint 数量不够造成的。

(内心还是希望芯片是支持的，不然就只能换芯片了 T_T）

baidxi LV 2

@wuhanstudio 改UDC驱动，UDC驱动已经几百年没更新了。如果确定硬件端点够，改一下就可以了。

uuuuid LV 6

@wuhanstudio

就是说D1 / D1s 可以模拟摄像头吗?

wuhanstudio LV 3

@uuuuid 是的，D1s 加载 g_webcam 模块后用 v4l2-ctl --list-devices 会出现虚拟的摄像头设备，可惜 H2/H3/H5 会报错 invalid argument -22，虽然只是少了2个端点

tigger LV 7

@wuhanstudio
确实, V3s 也不行:

V3s Linux4.13执行modprobe g_webcam 出现端点错误, 是端点不够吗? 其他的 g_serial/g_ffs没问题
https://whycan.com/t_2915.html

wuhanstudio LV 3

@tigger 不太确定是不是端点不够，D1s 有 10 个端点可以使用，但是 BCM2835 只有 8 个端点也能正常使用，H3 也是 8 个端点就报错了

aozima LV 7

有复合设备吗？把不必要的复合设备关掉，看能不能减少端点占用。

wuhanstudio LV 3

@aozima 多谢提醒，我检查了一下 configfs 只配置了 720p 的 MPJEG 摄像头设备，没有复合设备：

https://github.com/wuhanstudio/adversarial-camera/blob/master/configfs/usb-gadget.sh

发现 Invalid argument -22 报错就是最后一行无法配置 (Allwinner H2, H3, H5)：

ls /sys/class/udc > /sys/kernel/config/usb_gadget/pi4/UDC

wuhanstudio LV 3

@uuuuid 我最近又试了一下，D1s 可以配置 USB Gadget 为摄像头，配置好之后 uvc-gadget 也可以启动，连接到 Windows 后检测到新设备，设备管理器出现了 UVC Camera，但是一旦打开摄像头软件 D1s 就会报错无法接收数据，暂时还没找到原因.

https://github.com/wuhanstudio/adversarial-camera/tree/master/uvc-gadget


# ./uvc-gadget -u /dev/video2  -v /dev/video0 -f 1 -r 1
Format: 1 0:YUYV 1:MJPEG
V4L2 device is USB 2.0 Camera: USB Camera on bus usb-sunxi-ehci-1
V4L2: Getting current format: MJPG 1280x720
V4L2: Setting format to: MJPG 1280x720
V4L2: Getting current format: MJPG 1280x720
v4l2 open succeeded, file descriptor = 3
uvc device is sunxi_usb_udc on bus gadget
uvc open succeeded, file descriptor = 4
V4L2: Buffer 0 mapped at address 0x3fc64ca000, length 1843789.
V4L2: Buffer 1 mapped at address 0x3fc6307000, length 1843789.
V4L2: 2 buffers allocated.
[  219.698224] sunxi_set_cur_vol_work()394 WARN: get power supply failed
[  219.744990] android_work: sent uevent USB_STATE=CONNECTED
[  219.773589] configfs-gadget gadget: high-speed config #2: c
[  219.779827] configfs-gadget gadget: uvc: uvc_function_set_alt(0, 0)
[  219.786814] configfs-gadget gadget: uvc: reset UVC Control
[  219.792940] configfs-gadget gadget: uvc: uvc_function_set_alt(1, 0)
[  219.800053] configfs-gadget gadget: uvc: uvc_function_set_alt(1, 0)
[  219.821854] configfs-gadget gadget: uvc: uvc_function_set_alt(1, 0)
control request (req 81 cs 02)
control request (req 81 cs 02)
control request (req 81 cs 02)
[  219.838593] android_work: sent uevent USB_STATE=CONFIGURED
[  221.116837] sunxi_vbus_det_work()3292 WARN: get power supply failed
[  221.123844] configfs-gadget gadget: uvc: uvc_function_disable()
[  221.148585] android_work: sent uevent USB_STATE=DISCONNECTED
[  610.318603] ERR: Operation not supported
[  610.323187] ERR: Operation not supported
[  610.336907] android_work: sent uevent USB_STATE=CONNECTED
[  611.706855] sunxi_vbus_det_work()3292 WARN: get power supply failed
[  611.726906] android_work: sent uevent USB_STATE=DISCONNECTED
[  612.041672] ERR: Operation not supported
[  612.046235] ERR: Operation not supported
[  612.056868] android_work: sent uevent USB_STATE=CONNECTED
[  612.663794] ERR: Operation not supported
[  612.668374] ERR: Operation not supported
[  613.916841] sunxi_vbus_det_work()3292 WARN: get power supply failed
[  613.936900] android_work: sent uevent USB_STATE=DISCONNECTED
[  614.354751] ERR: Operation not supported
[  614.359314] android_work: sent uevent USB_STATE=CONNECTED
[  614.365351] ERR: Operation not supported
[  615.756834] sunxi_vbus_det_work()3292 WARN: get power supply failed
[  615.776902] android_work: sent uevent USB_STATE=DISCONNECTED
[  616.039829] ERR: Operation not supported
[  616.044524] ERR: Operation not supported
[  616.056874] android_work: sent uevent USB_STATE=CONNECTED
[  616.686031] ERR: Operation not supported
[  616.690586] ERR: Operation not supported
[  617.946849] sunxi_vbus_det_work()3292 WARN: get power supply failed
[  617.966909] android_work: sent uevent USB_STATE=DISCONNECTED

wuhanstudio LV 3

@baidxi 最新定位到 D1s 报错在 sunxi_udc.c (能识别到新 UVC 摄像头设备，但是没有数据):

ret = dev->driver->setup(&dev->gadget, crq);

上面这一行返回了 -EOPNOTSUPP, 完整代码：

buildroot/dl/linux/git/drivers/usb/sunxi_usb/udc/sunxi_udc.c
Line 1383:  DMSG_PANIC("ERR: Operation not supported\n");

        spin_unlock(&dev->lock);
        ret = dev->driver->setup(&dev->gadget, crq);
        spin_lock(&dev->lock);
        if (ret < 0) {
                if (dev->req_config) {
                        DMSG_PANIC("ERR: config change %02x fail %d?\n",
                                crq->bRequest, ret);
                        return;
                }

                if (ret == -EOPNOTSUPP)
                        DMSG_PANIC("ERR: Operation not supported\n");
                else
                        DMSG_PANIC("ERR: dev->driver->setup failed. (%d)\n",
                                ret);

                udelay(5);

                USBC_Dev_ReadDataStatus(
                                g_sunxi_udc_io.usb_bsp_hdle,
                                USBC_EP_TYPE_EP0, 1);
                USBC_Dev_EpSendStall(
                                g_sunxi_udc_io.usb_bsp_hdle,
                                USBC_EP_TYPE_EP0);

                dev->ep0state = EP0_IDLE;
                /* deferred i/o == no response yet */
        } else if (dev->req_pending) {
                dev->req_pending = 0;
        }

cola123456 LV 4

@memory [ 98.945505] handle_ep0: ep0 setup end
[ 104.065802] handle_ep0: ep0 setup end请问这个是端点不够的意思吗？

xuxxxxx LV 3

@wuhanstudio 这个有进展吗？我遇到了相同的情况

chengwei_peng LV 6

usb摄像头一般是USB ISO模式传输的，可能usb驱动将端点配置为BULK模式了，可以试试修改底层的usb驱动，drivers/usb/sunxi_usb/include/sunxi_udc.h和drivers/usb/sunxi_usb/udc/sunxi_udc.c，将ep5in_bulk_name修改为iso。

xuxxxxx LV 3

@chengwei_peng
做了这样的改动:

sunxi_udc.h
sunxi_udc.c

问题还是存在，改动应该没问题吧？