Re: [2.6.27-rc] USB storage: hangs and massive dmesg spews

From: Alan Stern
Date: Fri Aug 08 2008 - 17:53:23 EST


On Fri, 8 Aug 2008, Jeff Garzik wrote:

> Running kernel 2.6.27-rc1-00156-g94ad374 on x86-64, I
>
> 1) plugged in a USB device
>
> > Aug 8 15:32:03 core kernel: usb 1-8: new high speed USB device using ehci_hcd a
> > nd address 4
> > Aug 8 15:32:04 core kernel: usb 1-8: configuration #1 chosen from 1 choice
> > Aug 8 15:32:04 core kernel: usb 1-8: New USB device found, idVendor=041e, idPro
> > duct=4155
> > Aug 8 15:32:04 core kernel: usb 1-8: New USB device strings: Mfr=1, Product=2,
> > SerialNumber=3
> > Aug 8 15:32:04 core kernel: usb 1-8: Product: ZEN Stone Plus
> > Aug 8 15:32:04 core kernel: usb 1-8: Manufacturer: CREATIVE
> > Aug 8 15:32:04 core kernel: usb 1-8: SerialNumber: F03A09331004CD04
> > Aug 8 15:32:04 core kernel: Initializing USB Mass Storage driver...
> [...]
> > scsi 10:0:0:0: Direct-Access CREATIVE ZEN Stone Plus 1031 PQ: 0 ANSI: 4
> > sd 10:0:0:0: [sdc] 963968 2048-byte hardware sectors (1974 MB)
> > sd 10:0:0:0: [sdc] Write Protect is off
> > sd 10:0:0:0: [sdc] Mode Sense: 38 00 00 00
> > sd 10:0:0:0: [sdc] Assuming drive cache: write through
>
>
> 2) I executed: sudo dd if=/dev/sdc of=foo.img bs=32k
>
>
> 3) judging from ls(1), the entire storage device's contents was
> successfully dumped to my hard drive. HOWEVER, dd(1) sat in disk wait,
> failing to end execution once the end of the USB storage device was reached.
>
>
> 4) a huge amount of dmesg spew followed. at the time of this writing,
> the following spew has been passed to dmesg over TWO HUNDRED times:
>
> > Aug 8 15:41:01 core kernel: INFO: task usb-storage:21894 blocked for more than
> > 120 seconds.

This has been fixed in 2.6.27-rc2.

Alan Stern

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