Kernel panic when copying data to umass device (USB4BSD) - problem found

Alexey Shuvaev shuvaev at
Fri Nov 7 11:19:32 PST 2008

On Fri, Nov 07, 2008 at 06:11:26PM +0100, Hans Petter Selasky wrote:
> Hi Jeremy,
> I've reproduced the issue with some mods to the usb2_busdma.c on 32-bit 
> arcitecture and have made a fix for this problem.
> Try the following patch and re-test!
Thanks a lot! I have rebuild the kernel with this patch
and so far no panics. Indeed, the system I am using is amd64 with 4Gb of RAM.

> Some mem-stick benchmarks would be nice ...
What exactly do you mean?
I have done:
dd if=file_on_one_stick of=/dev/null bs=1m (12.5 Mb/s)
dd if=/dev/random of=file_on_the_stick bs=1m count=128 (2.6 Mb/s)

and the same tests with USB-microSDHC adapter with 8Gb card
(20 MB/s read, 15 Mb/s write).

Anything else?


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