From: Bernhard Kaindl <bk@fsfe.org>
Date: Wed, 6 Sep 2006 12:58:30 +0000 (+0200)
Subject: ohci1394: steps to implement suspend/resume
X-Git-Tag: v2.6.20-rc1~34^2~412^2^2~51
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f011bf085cd41ee40c2c8e530f801ac6cb6e00d0;p=pandora-kernel.git

ohci1394: steps to implement suspend/resume

I did a quick shot on what I described and the appended patch
does the first thing needed for working suspend/resume
in ohci1394 which is HW de- and re-initialisation.

It works with suspend2disk on my Ricoh R5C552 IEEE 1394 Controller
with the 2.6.17 kernel to the extent that if I call dvgrab --interactive
after suspend2disk without unloading ohci1394, it does not lock up
dvgrab with 100% CPU but properly connects to the camera, given
that I first unplug and plug the camera after coming back from
suspend.

I guess that could be fixed by forcing a bus reset in the resume
function.

I cannot test suspend to RAM here at the moment and should
follow the guidelines in Documentation/power/pci.txt also,
so this is rather a quick report than a finished patch and
there are some rough edges:

However, with this patch, I have to unload at least some in-kernel
users of ohci1394 like dv1394 or video1394 before suspending.

Not doing that caused an Oops and a bad tasklet error, probably from
not handling ISO tasklets during suspend/resume properly.

Maybe these can be temporarily cleared or unregistered and
re-registered for suspend/resume with help from the other
layers or from the highlevel 1394 core, but I do not really
know what these do.

But this patch provides a useful base to start from and is
already of much help for people which do not need dv1394
and video1394 or can unload them at least during suspend.

I cannot test function with sbp2 at the moment, but raw1394
seems to work fine.

Signed-off-by: Bernhard Kaindl <bk@fsfe.org>

Update 1: merge with previous two ohci1394 suspend/resume patches
Update 2: version for application on top of Linux 2.6.19-rc4

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---

Reading git-diff-tree failed