使用sdk8.0，usb1配置为host接口，下边接hub芯片。遇到的问题是，在系统启动之前插U盘可以识别，启动后，拔掉U盘有打印信息，但是再插上就没有反应了。使用fdisk -l命令查看无U盘信息。
背景：同一块板子，使用之前的4.6的sdk一切正常。所以可以排除硬件问题。
能否给个调试思路？？
linux启动部分log信息如下：
[ 2.374847] rtc-pcf8563 2-0051: setting system clock to 2015-03-20 11:18:33 UTC (1426850313) [ 2.386963] ALSA device list: [ 2.390099] No soundcards found. [ 2.572839] usb 2-1: new high-speed USB device number 2 using musb-hdrc [ 2.653262] kjournald starting. Commit interval 5 seconds [ 2.666801] EXT3-fs (mmcblk0p2): using internal journal [ 2.679779] EXT3-fs (mmcblk0p2): recovery complete [ 2.684925] EXT3-fs (mmcblk0p2): mounted filesystem with ordered data mode [ 2.692327] VFS: Mounted root (ext3 filesystem) on device 179:2. [ 2.702766] devtmpfs: mounted [ 2.707038] Freeing unused kernel memory: 268K (c07ca000 - c080d000) [ 2.714160] usb 2-1: New USB device found, idVendor=0424, idProduct=2514 [ 2.721299] usb 2-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 [ 2.735521] hub 2-1:1.0: USB hub found [ 2.740565] hub 2-1:1.0: 4 ports detected INIT: version 2.88 booting [ 3.022684] usb 2-1.3: new high-speed USB device number 3 using musb-hdrc [ 3.143382] usb 2-1.3: New USB device found, idVendor=0781, idProduct=5567 [ 3.150715] usb 2-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 3.158465] usb 2-1.3: Product: Cruzer Blade [ 3.162997] usb 2-1.3: Manufacturer: SanDisk [ 3.167496] usb 2-1.3: SerialNumber: 20044317430CE4D08886 [ 3.185146] usb-storage 2-1.3:1.0: USB Mass Storage device detected [ 3.203437] scsi0 : usb-storage 2-1.3:1.0 Starting udev [ 3.373951] udev[944]: starting version 164 [ 3.620705] remoteproc0: failed to load am335x-pm-firmware.elf [ 3.627025] remoteproc0: powering up wkup_m3 [ 3.631622] remoteproc0: Direct firmware load failed with error -2 [ 3.638183] remoteproc0: Falling back to user helper [ 4.204429] scsi 0:0:0:0: Direct-Access SanDisk Cruzer Blade 1.26 PQ: 0 ANSI: 6 [ 4.314675] sd 0:0:0:0: [sda] 15633408 512-byte logical blocks: (8.00 GB/7.45 GiB) [ 4.328993] sd 0:0:0:0: Attached scsi generic sg0 type 0 [ 4.389663] sd 0:0:0:0: [sda] Write Protect is off [ 4.446534] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 4.688173] remoteproc0: request_firmware failed: -2 [ 4.693608] wkup_m3 44d00000.wkup_m3: rproc_boot failed [ 4.753132] sda: sda1 [ 4.895792] sd 0:0:0:0: [sda] Attached SCSI disk [ 6.459825] FAT-fs (mmcblk0p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck. [ 6.556499] random: nonblocking pool is initialized [ 6.668975] FAT-fs (sda1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.
