Re: Possible issue with commit: "clockevents: Set noop handler inclockevents_exchange_device()"

From: Tim Gardner
Date: Sat Dec 24 2011 - 10:16:18 EST


On 12/23/2011 06:20 PM, Joseph Salisbury wrote:
Hi Thomas,

We have been working on a bug[1] that affects suspend/resume. After
running some tests, it appears the regression has to do with a commit
you submitted:


commit b01b383bbd04e9dcf7d9fe6ca3751b77ccdc533c
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Fri Dec 2 16:02:45 2011 +0100

clockevents: Set noop handler in clockevents_exchange_device()

commit de28f25e8244c7353abed8de0c7792f5f883588c upstream.

If a device is shutdown, then there might be a pending interrupt,
which will be processed after we reenable interrupts, which causes the
original handler to be run. If the old handler is the (broadcast)
periodic handler the shutdown state might hang the kernel completely.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>


We tested with this commit reverted in the 3.0.13 kernel and the
suspend/resume bug went away. We also tested the 3.2-rc6 kernel with
this commit reverted and the bug went away there as well.

I wanted to let you know about this issue and see if there is any
additional details you might need from me.

Thanks,

Joe



[1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/904569


To be clear, this regression appears to exist in the 3.2-rc6: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/904569/comments/24

Cc'ing LKML

rtg
--
Tim Gardner tim.gardner@xxxxxxxxxxxxx
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