On Sat, 12 Jan 2013, Alex Riesen wrote: > On Fri, Jan 11, 2013 at 10:04 PM, Alex Riesen <raa.lkml@xxxxxxxxx> wrote: > > Hi, > > > > the USB stick (an Cruzer Titanium 2GB) was not recognized at any of > > the USB ports of this system (an System76 lemu4 laptop, XHCI device) > > after it was removed. If I attempt to insert it again in any of the > > ports (one of the two USB3, or the USB2) the led on the stick lights > > up shortly and if off again. There is no media detection messages in > > the dmesg output, only that from the first time: To make testing simpler, use only the USB-2 ports. The xHCI driver is not as mature as the EHCI driver. > > usb 1-1.2: new high-speed USB device number 3 using ehci-pci > > usb 1-1.2: New USB device found, idVendor=0781, idProduct=5408 > > usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 > > usb 1-1.2: Product: U3 Titanium > > usb 1-1.2: Manufacturer: SanDisk Corporation > > usb 1-1.2: SerialNumber: 0000187A3A60F1E9 > > scsi6 : usb-storage 1-1.2:1.0 > > io scheduler deadline registered (default) > > usb 1-1.2: USB disconnect, device number 3 > > > > The kernel is v3.8-rc3. I never had this problem in 3.7. I could almost > > reproduce the problem later in a simplified setup (init=/bin/bash) on > > USB3 ports by inserting and removing the stick quickly. Almost - because > > the USB3 ports recovered after some time, while the USB2 port never > > experienced the problem. For testing, use a kernel with CONFIG_USB_DEBUG and CONFIG_PRINTK_TIME enabled. Do the following: After a normal boot, run "dmesg -C" to clear the log buffer. Then plug in the stick. After a couple of seconds, type Alt-SysRq-W. Then unplug the stick. After a couple of seconds, type Alt-SysRq-W again. Then collect the output from dmesg and post it. > One more detail: I usually use the "noop" elevator. That time it was > the "deadline". And I just reproduced it easily with "deadline". I doubt the elevator has anything to do with this. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
