USB crappiness?

[Bryan Liesner]

On Sat, 19 Jul 2003, Juli Mallett wrote:

> Hi,
>
> I tried to upgrade my workstation to current recently, and I have to
> use a lot of USB, and while using some USB mass storage device, with
> a UFS filesystem on it, and doing a large operation to it (tar c|tar x)
> everything deadlocked on ufs, the USB stack blew up, and upon causing
> an interrupt to it, it panicked, and panic pagefaulted.
>
> Anyone else seeing these sorts of cohesive fallovers?
>
> Thanx,
> juli.
>

Yes, I can confirm that.  I do an nightly dump to a file on my USB
hard disk (ehci).  I woke up to find a screen full of read errors, and
at first I thought the disk went belly up.  I reverted back and it was
working fine.  I/O speed has _seriously_ degraded as well.  Prior to
the bus dma patches, I was getting a little better than 8 MB/s writes to
the disk, afterwards, less than 2 MB/s.  The "performance hit"
discussed prior to the commit is a bit of an understatement.

-Bryan