[arch-general] Unable to mount external USB HD from two of my USB ports

[Rodrigo Rivas]

On Fri, Oct 19, 2012 at 8:16 AM, Robbie Smith <zoqaeski at gmail.com> wrote:

> I've been having troubles mounting an external USB HDD to two of the three
> USB ports on my laptop. dmesg reports a timeout connecting to the device;
> plugging in other devices to the same ports works fine with no errors. I've
> attached the log here[1].
>
> The drive in question is a Seagate 1.5 TB Expansion Portable Drive, model
> ST1500LM003-9YH148. I reformatted it upon purchase to have two partitions,
> a NTFS one for Windows compatibility, and an Ext4 one for Linux backups and
> miscellanea. Each partition is ~750GB in size.
>
> Any idea what is going on? I think the issue may be with the drive, which
> is virtually brand new (I bought it ~3 months ago).
>
> [1] https://gist.github.com/3916478
>

Look at the working Verbatim drive:

#Left:

[ 1689.742443] usb 3-1: new high-speed USB device number 2 using xhci_hcd
#Right:

[ 2115.686272] usb 5-1: new high-speed USB device number 4 using ehci_hcd

See any difference? Yes, one is Xhci and the other Ehci. AFAIK the
xhci is USB3 and the ehci is USB2. So it seems that your HD is trying
to use USB3 but it is failing. The other port, however, uses ehci
directly and works fine.

I guess that blacklisting the xhci-hcd driver should may it fallback
to ehci and just work, but I don't have any USB3 device or
motherboard, so I cannot tell for sure.

Other option is to disable the USB3 support in the BIOS, if you can
find such an option.

HTH
--
Rodrigo