Subject: Re: umass problems with camera
To: Alan Barrett <firstname.lastname@example.org>
From: Steven M. Bellovin <email@example.com>
Date: 11/05/2003 13:44:40
In message <20031029073626.GC1019@apb.cequrux.com>, Alan Barrett writes:
>On Tue, 28 Oct 2003, Jeff Rizzo wrote:
>> I *know* I had this camera working a few days ago, and as far as I
>> know nothing has changed. Now, I get:
>> umass0 at uhub4 port 3 configuration 1 interface 0
>> umass0: OLYMPUS C-4040ZOOM, rev 1.10/1.00, addr 6
>> umass0: using SCSI over Bulk-Only
>> umass0: no buffer memory
>> Any thoughts?
>The scsi-over-umass layer is failing to allocate a large block of kernel
>memory. It's much more likely to succeed if the umass* device is
>plugged in at boot time.
>This is an old bug, which used to be silent, but now produces the "no
>buffer memory" message.
Is this the cause of USB mass storage devices silently doing nothing
useful when they're plugged in? I'm glad it's been found, and a
message is better than nothing, but is a better fix possible? In
particular, is there some way that that some amount of space can be
reserved at boot time for later use by USB storage devices?
--Steve Bellovin, http://www.research.att.com/~smb