Re: Issue mounting USB mass-storage drive

[Brad Spencer <brad%anduin.eldar.org@localhost>]

Bruce Nagel <nagelbh%SDF.ORG@localhost> writes:

> On Fri, 28 Dec 2018, Michael van Elst wrote:
>
>> Date: Fri, 28 Dec 2018 08:45:15 -0000 (UTC)
>> From: Michael van Elst <mlelstv%serpens.de@localhost>
>> To: netbsd-users%netbsd.org@localhost
>> Newsgroups: lists.netbsd.users
>> Subject: Re: Issue mounting USB mass-storage drive
>
>> nagelbh%sdf.org@localhost (Bruce Nagel) writes:
>
>>> umass0: failed to create xfers
>
>> Usually means the kernel ran out of (contigous) memory. This can be
>> a consequence of using USB3, the xhci driver does not support
>> multi-segment DMA yet.
>
>> It should only happen after some larger uptime when kernel memory
>> might be too fragmented.
>
> 'Turning it off and back on' did resolve the issue, so probably 'myth 
> confirmed'. :-)  I had an uptime beyond a month when this issue presented 
> itself.  Trying again the next day after rebooting allowed mounting the 
> drive it is still working okay.
>
> I'm guessing there isn't a simple means to use USB2 drivers and avoid this 
> issue?  Nothing in the case is newer than 2012 so I don't need USB3 
> support.
>
> Thanks,
> Bruce


I see this with a USB2 8.x only system, so simply not doing USB3 may not
really help the situation.  My more -current systems with USB3 actually
do not exhibit this issue at all, but they also have a lot more memory.



-- 
Brad Spencer - brad%anduin.eldar.org@localhost - KC8VKS - http://anduin.eldar.org