TI中文支持网自己做的板子，USB口插上鼠标可以使用，但是插上优盘就不能工作。
linux内核配置肯定是没问题的，我的配置按照这个文档检查过，该选的都选上了：http://processors.wiki.ti.com/index.php/UsbConfigHostMSC
另外也用SDK里最原始未改过的.config试过，结果也一样。也可以排除优盘的问题，试过好几个优盘了。
插上优盘，串口就会出现如下打印：
[ 596.043385] usb 1-1: new high-speed USB device number 17 using musb-hdrc
[ 596.103419] hub 1-0:1.0: unable to enumerate USB device on port 1
[ 596.383361] usb 1-1: new high-speed USB device number 18 using musb-hdrc
[ 596.443384] hub 1-0:1.0: unable to enumerate USB device on port 1
[ 596.723357] usb 1-1: new high-speed USB device number 19 using musb-hdrc
[ 596.783376] hub 1-0:1.0: unable to enumerate USB device on port 1
[ 597.063357] usb 1-1: new high-speed USB device number 20 using musb-hdrc
[ 597.123373] hub 1-0:1.0: unable to enumerate USB device on port 1
[ 597.403356] usb 1-1: new high-speed USB device number 21 using musb-hdrc
[ 597.463374] hub 1-0:1.0: unable to enumerate USB device on port 1
[ 597.743357] usb 1-1: new high-speed USB device number 22 using musb-hdrc
[ 597.803374] hub 1-0:1.0: unable to enumerate USB device on port 1
[ 598.083379] usb 1-1: new high-speed USB device number 23 using musb-hdrc
[ 598.143411] hub 1-0:1.0: unable to enumerate USB device on port 1
[ 598.423360] usb 1-1: new high-speed USB device number 24 using musb-hdrc
[ 598.483388] hub 1-0:1.0: unable to enumerate USB device on port 1
我手头上有一块StarterKit，同一个优盘插在StarterKit上就能用，StarterKit串口打印如下：
[ 454.136413] usb 1-1: new high-speed USB device number 3 using musb-hdrc
[ 454.276611] usb 1-1: config 1 interface 0 altsetting 0 bulk endpoint 0x81 has invalid maxpacket 256
[ 454.286041] usb 1-1: config 1 interface 0 altsetting 0 bulk endpoint 0x1 has invalid maxpacket 256
[ 454.295867] usb 1-1: New USB device found, idVendor=071b, idProduct=3203
[ 454.302856] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 454.310333] usb 1-1: Product: ROCK MP3
[ 454.314208] usb 1-1: Manufacturer: RockChip
[ 454.318603] usb 1-1: SerialNumber: USBV1.00
[ 454.332702] usb-storage 1-1:1.0: Quirks match for vid 071b pid 3203: 400
[ 454.339904] scsi1 : usb-storage 1-1:1.0
[ 455.357299] scsi 1:0:0:0: Direct-Access RockChip USB MP3 1.00 PQ: 0 ANSI: 0
[ 455.372863] sd 1:0:0:0: [sda] 7929856 512-byte logical blocks: (4.06 GB/3.78 GiB)
[ 455.392944] sd 1:0:0:0: [sda] Write Protect is off
[ 455.407775] sd 1:0:0:0: [sda] No Caching mode page present
[ 455.413513] sd 1:0:0:0: [sda] Assuming drive cache: write through
[ 455.424133] sd 1:0:0:0: [sda] No Caching mode page present
[ 455.429901] sd 1:0:0:0: [sda] Assuming drive cache: write through
[ 455.438049] sda:
[ 455.443847] sd 1:0:0:0: [sda] No Caching mode page present
[ 455.449645] sd 1:0:0:0: [sda] Assuming drive cache: write through
[ 455.455993] sd 1:0:0:0: [sda] Attached SCSI removable disk
Hui Yin：
补充一下最新发现：
在代码里加打印逐步查找故障，发现函数hub_port_reset() 返回值 -107 (-ENOTCONN)
继续查找，发现函数usb_control_msg() 返回值 -19 (-ENODEV)
再继续，最终找到了这个函数里面：musb_urb_enqueue()，失败原因是 musb->is_active 为零，见下面红色部分。
至此没法再跟踪下去了，请看一下这是怎么回事。
static int musb_urb_enqueue( struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags){ unsigned long flags; struct musb *musb = hcd_to_musb(hcd); struct usb_host_endpoint *hep = urb->ep; struct musb_qh *qh; struct usb_endpoint_descriptor *epd = &hep->desc; int ret; unsigned type_reg; unsigned interval;
/* host role must be active */ if (!is_host_active(musb) || !musb->is_active) return -ENODEV; spin_lock_irqsave(&musb->lock, flags); ret = usb_hcd_link_urb_to_ep(hcd, urb); qh = ret ? NULL : hep->hcpriv; if (qh) urb->hcpriv = qh;
INIT_LIST_HEAD(&urb->giveback_list); spin_unlock_irqrestore(&musb->lock, flags);
Yaoming Qin：
回复 Hui Yin:
插u盘的时候，有vbus上有供电吗，你的电路设计和EVM板上一样吗
Hui Yin：
回复 Yaoming Qin:
VBUS上是有电的，用示波器测了，插上优盘的前后始终都有5V电压。
下面是USB部分的原理图，你看一下有没有问题。
怎么鼠标可以工作，优盘就不行呢？
Hui Yin：
回复 Hui Yin:
我把ESD保护器件U4以及串联的两个电阻去掉了，直接用铜线飞过去。
现在可以认到有优盘，但是/dev目录下仍然没有优盘的设备文件。
这是现在的串口打印信息。
[ 128.693106] usb 2-1: new high-speed USB device number 4 using musb-hdrc[ 128.888655] usb 2-1: config 1 interface 0 altsetting 0 bulk endpoint 0x81 has invalid maxpacket 256[ 128.898125] usb 2-1: config 1 interface 0 altsetting 0 bulk endpoint 0x1 has invalid maxpacket 256[ 128.960367] usb 2-1: New USB device found, idVendor=071b, idProduct=3203[ 128.967381] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3[ 128.974838] usb 2-1: Product: ROCK MP3[ 128.978746] usb 2-1: Manufacturer: RockChip[ 128.983115] usb 2-1: SerialNumber: USBV1.00[ 129.002549] usb-storage 2-1:1.0: Quirks match for vid 071b pid 3203: 400[ 129.010004] scsi2 : usb-storage 2-1:1.0
再把上面帖子里提到的正常打印放在这里对比一下，现在的打印信息还是少了后面的一些内容。
这是什么原因呢？
[ 454.136413] usb 1-1: new high-speed USB device number 3 using musb-hdrc[ 454.276611] usb 1-1: config 1 interface 0 altsetting 0 bulk endpoint 0x81 has invalid maxpacket 256[ 454.286041] usb 1-1: config 1 interface 0 altsetting 0 bulk endpoint 0x1 has invalid maxpacket 256[ 454.295867] usb 1-1: New USB device found, idVendor=071b, idProduct=3203[ 454.302856] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3[ 454.310333] usb 1-1: Product: ROCK MP3[ 454.314208] usb 1-1: Manufacturer: RockChip[ 454.318603] usb 1-1: SerialNumber: USBV1.00[ 454.332702] usb-storage 1-1:1.0: Quirks match for vid 071b pid 3203: 400[ 454.339904] scsi1 : usb-storage 1-1:1.0[ 455.357299] scsi 1:0:0:0: Direct-Access RockChip USB MP3 1.00 PQ: 0 ANSI: 0[ 455.372863] sd 1:0:0:0: [sda] 7929856 512-byte logical blocks: (4.06 GB/3.78 GiB)[ 455.392944] sd 1:0:0:0: [sda] Write Protect is off[ 455.407775] sd 1:0:0:0: [sda] No Caching mode page present[ 455.413513] sd 1:0:0:0: [sda] Assuming drive cache: write through[ 455.424133] sd 1:0:0:0: [sda] No Caching mode page present[ 455.429901] sd 1:0:0:0: [sda] Assuming drive cache: write through[ 455.438049] sda:[ 455.443847] sd 1:0:0:0: [sda] No Caching mode page present[ 455.449645] sd 1:0:0:0: [sda] Assuming drive cache: write through[ 455.455993] sd 1:0:0:0: [sda] Attached SCSI removable disk
Hui Yin：
回复 Hui Yin:
现在USB的差分线上已经没有任何其它东西了，5V电源也正常，硬件方面好像没什么可尝试的了。
能认出设备，但是/dev没有设备文件。从打印来看，USB这块儿是没问题的，问题出在SCSI那里，应该是个软件问题。
刚才又核对了一遍内核配置，文档里要求的那几个选项都选上了。
除了文档里提到的这几个选项之外，是不是还有什么必须选的？
Richie jemi：
LZ您好，请问你们还有AM335X系列的CPU吗?能否卖我们几片，现在我们公司项目急用，官方申请太慢了，来不及
