s3c2410的usb host不稳定的解决方法 [转贴]

jackzheng2002

s3c2410的usb host不稳定的解决方法
h_falls 所做的工作，表示感谢！

今天花了一些时间研究, 觉得可能是s3c2410芯片本身的问题, 导致启动时无法正确初始化UPLLCON寄存器,使之给USB输出48.00MHz的时钟频率, 于是我修改了下driver/usb/usb.c的代码:
/*************************/
--- drivers/usb/usb.c 2004-07-27 16:59:28.000000000 +0800
+++ ../kerne-1version/drivers/usb/usb.c 2004-07-03 15:15:32.000000000 +0800
@@ -38,13 +38,6 @@
#endif
#include <linux/usb.h>

-#include <asm/hardware.h>
-#include <asm/irq.h>
-#include <asm/io.h>
-#include <asm/pci.h>
-#define OHCI_HW_DRIVER 1
-#include "usb-ohci.h"
-
static const int usb_bandwidth_option =
#ifdef CONFIG_USB_BANDWIDTH
1;
@@ -2268,15 +2261,6 @@
dev->epmaxpacketout[0] = 8;

err = usb_set_address(dev);
- if( err < 0 )
- {
- CLKCON &= ~CLKCON_USBH;
- UPLLCON = FInsrt(0x78, fPLL_MDIV) | FInsrt(0x02, fPLL_PDIV) | FInsrt(0x03, fPLL_SDIV);
- CLKCON |= CLKCON_USBH;
- err = usb_set_address(dev);
- printk("first usb_set_address error\n");
-
- }
if (err < 0) {
err("USB device not accepting new address=%d (error=%d)",
dev->devnum, err);


/************************/
使得再usb_set_address失败的时候,再设置一次UPLLCON,这样就不会有问题了, 另外我的driver/usb/usb-ohci-s3c2410.c用的是mizi.com上的2.4.19版本.

dmesg内容如下:
hub.c: 2 ports detected
hub.c: USB new device connect on bus1/1, assigned device number 2
first usb_set_address error ---- 这句话表明重新设置UPLLCON了
usb.c: USB device 2 (vend/prod 0xdd8/0x3) is not claimed by any active driver.
Initializing USB Mass Storage driver...
usb.c: registered new driver usb-storage
scsi0 : SCSI emulation for USB Mass Storage devices
Vendor: Model: Rev:
Type: Direct-Access ANSI SCSI revision: 02
Attached scsi removable disk sda at scsi0, channel 0, id 0, lun 0

可以看见, u盘被正确地找到了. 如果有人有更好的方法请指出,谢谢.