Re: Gnome Pilot Causing USB Drive problems (version 2.0.10)
- From: Nigel Metheringham <Nigel Metheringham dev intechnology co uk>
- To: The PalmOS integration pacakge <gnome-pilot-list gnome org>
- Subject: Re: Gnome Pilot Causing USB Drive problems (version 2.0.10)
- Date: Wed, 08 Sep 2004 14:15:38 +0100
On Wed, 2004-09-08 at 06:46 -0400, David A. Desrosiers wrote:
> > Won't help in this case. Its not when gnome-pilotd is talking to a
> > USB palm device, but when gnome-pilotd polling to see if a palm
> > device is attached. At that point (unless you have just hit hotsync
> > on the palm) the visor module isn't loaded.
>
> That depends on your system configuration. I've never yet run
> the visor driver on a sytem where it wasn't already loaded. hotplug
> causes FAR too many problems with Palm devices, and that is exactly
> why we strongly recommend disabling it if you use a USB-connected
> Palm.
OK, I have now managed to reproduce this problem with pretty much a bare
minimum around it.
If a program uses poll() and opens/stat/reads /proc/bus/usb/devices then
USB transfers appear to stutter/fail to USB Mass Storage or other bulk
USB users (I have a USB mouse which is unaffected). Use of poll() or
read or stat of the device file alone is not effective - you need all
three components.
I did not have the visor module loaded during these tests, so thats not
involved. The poll was looking at input from a FH opened on /dev/null
(so it wasn't doing much). I did see freezes on the open/read
of /proc/bus/usb/devices while this was happening - 4 or 5 second hangs.
If anyone wants my bit of perl which I am using as a test load generator
to show this problem then drop me a line - its only 30 or so lines.
I suspect that if gpilod was modded to drop the fstat() of
the /proc/bus/usb/devices file after opening it then the problem would
go away - I may try doing this later.
Nigel.
--
[ Nigel Metheringham Nigel Metheringham InTechnology co uk ]
[ - Comments in this message are my own and not ITO opinion/policy - ]
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