[sane-devel] Xsane can't find scanner - again, but this one is USB

[Johannes Meixner]

Hello,

an addedum FYI

On Nov 2 22:50 MR ZenWiz wrote (excerpt):
> On Fri, Oct 30 Olaf Meeuwissen <paddy-hack at member.fsf.org> wrote:
>>
>> Others have already commented on the fact the USB3 support and
>> the xhci kernel driver may be causing your trouble.
>>
> This could very well be - it's one of the white m/b ports
> labeled USB (not USB3), so I have to trust that--sort of.

Neither the color nor what the port is labeled on the computer
is reliable regarding what kernel driver is used for the port.

Only the "lsusb -t" output shows what kernel driver is used.

When "lsusb -t" shows "Driver=xhci_hcd" for the USB bus and port
where the USB scanner is connected, then there could be issues
depending on the computer hardware and firmware (BIOS or UEFI).

See
https://bugzilla.opensuse.org/show_bug.cgi?id=856794#c24
that reads (excerpt):
-----------------------------------------------------------------
My machine has 4 USB ports, two labeled with
the "super speed" USB logo (a.k.a. USB 3) and
two labeled with the normal USB logo (a.k.a. USB 2)
but for all 4 ports xhci is used and it fails on all 4 ports.
-----------------------------------------------------------------

All 4 USB ports on my testing machine have same dark color.
Also the "super speed" labeled ports are basically black.
Their exact color is "very dark" but not "100% black"
and neither blue (USB 3.0) nor teal blue (USB 3.1), cf.
https://en.wikipedia.org/wiki/USB#Colors

And see
https://bugzilla.opensuse.org/show_bug.cgi?id=856794#c40
that reads (excerpt):
-----------------------------------------------------------------
It depends on the computer hardware where "hardware"
includes the computer's firmware (BIOS or UEFI).

There are computers where USB3 always "just works".

There are computers where USB3 fails under certain conditions.

Perhaps there are computers where USB3 always fails.
-----------------------------------------------------------------


Kind Regards
Johannes Meixner
-- 
SUSE LINUX GmbH - GF: Felix Imendoerffer, Jane Smithard,
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