Dave (and others),
The kernel has several widespread bugs that are affecting all releases, that are impacting a lot of users.
- Hibernation There are so many bugs here it's hard to know where to begin.
- We have cases where it fails to sleep, or resumes instantly.
- There are cases where it looks to be working ok, but shortly after resuming, we see oopses/panics etc. It looks like something is scribbling over random parts of memory (usually landing on the dcache)
- For some of those cases, it's an i915 bug where disabling modesetting works around it. We've seen similar bugs from non-i915 hardware though.
Since about 3.0, I have been collecting - rather patiently - various hibernate-related kernel errors (I have about 8-9) and could email/send these if there is interest. I have also been logging various hibernate-related bugs with bugzilla for the past year or so.
This problem is the only one I have been experiencing with the kernel, but it has been going on for quite a while (since F8, I think - hibernate was an unmitigated disaster then). Admittedly, hibernate/restore is much more stable now, but nearly not stable-enough so that I could be confident to get to my desktop when I power up my PC after hibernate is done.
The machine I use hibernate on takes quite a hammering on a daily basis (it is on for at least 75 hours a week as most of my development work is done there) and it is very annoying when restore after hibernate fails and I have to start all over again. It does not happen as often as before, but it is not very stable either.
From my experience, I think the root of the problem is swap page/memory corruption during or shortly after hibernate/restore cycle. I was planning to allocate a separate partition on the hard disk just for hibernate, instead of using the swap partition as is the case now, to see whether the instability I am experiencing will go away.
Another issue I started experiencing just recently (since version 3.1 of the kernel was installed) - when I initiate hibernate, my PC powers down normally, but as soon as I switch my monitor off (press the off switch on the monitor itself), the computer starts up straight away! If I wait a while for the monitor to switch off "naturally" (i.e. after it switches off when it is not getting a video signal from the PC for about 10 seconds) then when I switch it off the PC stays off. Bizarre!
I did not experience this before and I am not sure whether the fact that I have usb hub on that monitor (which I do use) has anything to do with this rather peculiar behaviour.
Again, this seems unique to kernel versions 3.1 and above and I haven't changed my BIOS or anything on my configuration at all.
Just my 2p worth.