Android/Linux USB OTG U盘的挂载问题

问题：通过otg可以识别到USB鼠标，但插上U盘却不识别。

问题分析：怀疑是USB otg的menuconfig没有配置。

问题处理：

1、make menuconfig进入config的配置

2、配置路径如下：

Device Drivers ---> MMC/SD/SDIO card support ---->

然后选择: USB SD Host Controller (USHC) support ,

VUB300 USB to SDIO/SD/MMC Host Controller support

正确挂载u盘log如下：

[ 273.447143]{0} DEBUG:COMIP_HSIC_TIMER_SCHEDULE:: Modifying timer hc timer to expire in +10000 msec

[ 273.457336]{0} usb 2-1.3: device v090c p1000 is not supported

[ 273.463684]{0} usb 2-1.3: New USB device found, idVendor=090c, idProduct=1000

[ 273.472839]{3} usb 2-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 273.472869]{3} usb 2-1.3: Product: USB DISK

[ 273.472869]{3} usb 2-1.3: Manufacturer: SMI Corporation

[ 273.481231]{0} DEBUG:COMIP_HSIC_TIMER_SCHEDULE:: Modifying timer hc timer to expire in +10000 msec

[ 273.481262]{0} DEBUG:COMIP_HSIC_TIMER_SCHEDULE:: Modifying timer hc timer to expire in +10000 msec

[ 273.481689]{3} usb-storage 2-1.3:1.0: USB Mass Storage device detected

[ 273.491790]{3} scsi1 : usb-storage 2-1.3:1.0

[ 273.523864]{0} [hscdtd007a]:alps_poll flgSuspend 0

[ 273.625854]{0} [hscdtd007a]:alps_poll flgSuspend 0

[ 273.725982]{0} [hscdtd007a]:alps_poll flgSuspend 0

上面只是让otg识别到U盘，还要在adb里面进行如下操作，才能读取文件中的内容：

1、adb root

2、adb shell

3、mkdir /data/test

4、mount -t vfat /dev/block/sdb1 /data/test/

通常情况插入U盘后会在dev/block 下会有类似sdb4 或sda4 的节点。

注意：如果T卡在挂载的时候出现mount: Read-only file system，需要看一下是不是被写保护了。