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Bug#684630: linux-image-3.2.0-3-amd64: USB hard disk write speed is slow until I rmmod and modprobe ehci_hcd and uhci_hcd



On Sat, 2012-08-11 at 22:06 -0700, Robert Wall wrote:
> Package: src:linux
> Version: 3.2.21-3
> Severity: normal
> 
> Dear Maintainer,
> 
> My USB hard disk's write speed is slow (about 1MB/s) when I first boot
> Debian. It speeds up if I issue "rmmod ehci_hcd; rmmod uhci_hcd;
> modprobe ehci_hcd; modprobe uhci_hcd", to about 26MB/s. I suspect the
> issue is that uhci_hcd is being used instead of ehci_hcd because it's
> loaded first during boot, and it's limited to USB 1's maximum of
> 12Mb/s (which is close to the 1MB/s I was seeing).
> 
> I'd expect the system to autodetect whether it can use EHCI and prefer
> it if possible, or some other behavior more smart than defaulting to
> UHCI.

Yes, this is supposed to happen automatically.

> This issue recurs after reboot and is consistently reproducible.
[...]

Can you test whether this also happens in Linux 3.5 (packaged in
experimental)?

Can you provide the boot log (/var/log/dmesg) showing the initial
detection of the USB interfaces and hard disk?

Ben.

-- 
Ben Hutchings
Sturgeon's Law: Ninety percent of everything is crap.

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