usb 1-1: device descriptor read/64, error -62

不知道动了什么，内核启动的时候忽然打印出下面的错误信息：

usb 1-1: new full speed USB device using s3c2410-ohci and address 2
usb 1-1: device descriptor read/64, error -62
usb 1-1: device descriptor read/64, error -62
usb 1-1: new full speed USB device using s3c2410-ohci and address 3
usb 1-1: device descriptor read/64, error -62
usb 1-1: device descriptor read/64, error -62
usb 1-1: new full speed USB device using s3c2410-ohci and address 4
usb 1-1: device not accepting address 4, error -62
usb 1-1: new full speed USB device using s3c2410-ohci and address 5
usb 1-1: device not accepting address 5, error -62

 

在网上查了下说是UPLLCON赋值的问题。

 

试了些办法，最终延长了MPLLCON寄存器赋值和UPLLCON寄存器赋值之间延迟后解决了错误。

 

具体修改了以下代码：
vi uboot1.1.4/board/fl2440/fl2440.c

修改board_init函数以下语句:
        clk_power->MPLLCON = ((M_MDIV << 12) + (M_PDIV << 4) + M_SDIV);

        /* some delay between MPLL and UPLL */
        delay (4000);
       
        /* configure UPLL */
       clk_power->UPLLCON = ((U_M_MDIV << 12) + (U_M_PDIV << 4) + U_M_SDIV);
将其改为：
        clk_power->MPLLCON = ((M_MDIV << 12) + (M_PDIV << 4) + M_SDIV);

        /* some delay between MPLL and UPLL */
        delay (4000);

 

        delay (4000);
       
        /* configure UPLL */
        clk_power->UPLLCON = ((U_M_MDIV << 12) + (U_M_PDIV << 4) + U_M_SDIV);

 

也就是多加一个delay (4000);