上位機(jī)：ubuntu14.04 64bit
下位機(jī):qq2440
交叉編譯器:arm-linux-gcc 3.4.1
下位機(jī)使用的linux內(nèi)核版本:kernel2.6.13
1.插入u盤時(shí)錯(cuò)誤信息如下:
[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.解決方案如下:
2.1修改drivers/usb/host/ohci-s3c2410.c文件，添加以下內(nèi)容：
a.先添加頭文件#include mach/regs-clock.h>
b.在s3c2410_start_hc函數(shù)中添加以下內(nèi)容：
bash/shell Code復(fù)制內(nèi)容到剪貼板
- unsigned long upllvalue = (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函數(shù)如下:
bash/shell Code復(fù)制內(nèi)容到剪貼板
- static void s3c2410_start_hc(struct platform_device *dev, struct usb_hcd *hcd)
- {
- struct s3c2410_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);
- }
- }
- unsigned long upllvalue = (0x78 12) | (0x02 4) | (0x03);
- while (upllvalue != __raw_readl(S3C2410_UPLLCON)) {
- __raw_writel(upllvalue, S3C2410_UPLLCON);
- mdelay(1);
- }
- }
2.2總結(jié)：以上修改的函數(shù)功能是啟動(dòng)主機(jī)控制器,因?yàn)閡sb時(shí)鐘設(shè)置有問(wèn)題，因而在開啟主機(jī)控制器時(shí)修改時(shí)鐘,修改后的S3C2410_UPLLCON的值為0xF4100008;
3.注意：本版本內(nèi)核沒(méi)有頭文件regs-clock.h，因而我從其他內(nèi)核中復(fù)制過(guò)來(lái)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 ./
