上位机：ubuntu14.04 64bit

下位机:qq2440

交叉编译器:arm-linux-gcc 3.4.1

下位机使用的linux内核版本:kernel2.6.13

1.插入u盘时错误信息如下:

[root@FriendlyARM /home]# usb 1-1: new full speed USB device using s3c2410-ohci and address 6

usb 1-1: device descriptor read/64, error -110

usb 1-1: device descriptor read/64, error -110

usb 1-1: new full speed USB device using s3c2410-ohci and address 7

usb 1-1: device descriptor read/64, error -110

usb 1-1: device descriptor read/64, error -110

usb 1-1: new full speed USB device using s3c2410-ohci and address 8

usb 1-1: device not accepting address 8, error -110

usb 1-1: new full speed USB device using s3c2410-ohci and address 9

usb 1-1: device not accepting address 9, error -110

2.解决方案如下:

2.1修改drivers/usb/host/ohci-s3c2410.c文件，添加以下内容：

a.先添加头文件#include <mach/regs-clock.h>

b.在s3c2410_start_hc函数中添加以下内容：

bash/shell Code复制内容到剪贴板 unsignedlongupllvalue=(0x78<<12)|(0x02<<4)|(0x03); while(upllvalue!=__raw_readl(S3C2410_UPLLCON)){ __raw_writel(upllvalue,S3C2410_UPLLCON); mdelay(1); }

添加后的s3c2410_start_hc函数如下:

bash/shell Code复制内容到剪贴板 staticvoids3c2410_start_hc(structplatform_device*dev,structusb_hcd*hcd) { structs3c2410_hcd_info*info=dev->dev.platform_data; dev_dbg(&dev->dev,"s3c2410_start_hc:n"); clk_enable(clk); if(info!=NULL){ info->hcd=hcd; info->report_oc=s3c2410_hcd_oc; if(info->enable_oc!=NULL){ (info->enable_oc)(info,1); } } unsignedlongupllvalue=(0x78<<12)|(0x02<<4)|(0x03); while(upllvalue!=__raw_readl(S3C2410_UPLLCON)){ __raw_writel(upllvalue,S3C2410_UPLLCON); mdelay(1); } }

2.2总结：以上修改的函数功能是启动主机控制器,因为usb时钟设置有问题，因而在开启主机控制器时修改时钟,修改后的S3C2410_UPLLCON的值为0xF4100008;

3.注意：本版本内核没有头文件regs-clock.h，因而我从其他内核中复制过来的，命令如下:

jello@jello-Inspiron-N4050:~/Downloads/qq2440/linux/kernel-2.6.13$ cp /tftpboot/kernel-2.6.35.7/arch/arm/mach-s3c2410/include/mach/regs-clock.h ./