> In itself that timeout isn't necessarily bad, but in practice it usually
> seems to indicate a problem with EHCI. More extensive debugging
> information would help here. If it's not a host controller problem then
> we should be able to recover from the error. But without knowing what the
> cause is and what's happening, it's hard to say anything definite.
What's the host controller you're using? I used to see the same
problem here, but it went away altogether with a couple of patches
(which you seem to have applied) and a different EHCI controller.
> > About possible performance improvement on 2.5 ehci/usb-storage:
> > I've tested with 2.5.71, and I don't see a significant improvement over 2.4.
> > (Both are arround 7.7 MB/s for read, 10 MB/s for write). Disk can do arround
> > 40 MB/s reads on IDE.
>
> I don't know what's going on there.
I'm seeing the same speed here as well, and the disk can certainly do
more than 10MB/s sustained. I'm using the same USB-IDE bridge
(Genesys).
I'm not familiar with the way USB storage devices work, but I guess
you tell the disk to read from a certain location using a bulk OUT
transfer, then request a series of bulk INs to obtain the data. Since
INs are handled in a very funny way in USB (the data has to be there
already, otherwise the host gets a NAK), I wouldn't be surprised if
the USB-IDE bridge was at least part of the bottleneck here. Writes
are less problematic -- you just dump the data in bulk OUT packets and
the bridge writes to IDE whatever it can whenever it can.
As to write speed, I wouldn't expect much more than 10MB/s, since that
is what modern laptop drives can handle (I'm assuming you're using a
laptop drive?). 40MB/s seems more like a maximum for short bursts,
probably using the cache as well.
Andras
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Major Andras
e-mail: [EMAIL PROTECTED]
www: http://andras.webhop.org/
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