diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2010-06-07 17:53:51 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-02 10:29:46 -0700 |
commit | f5a3134583902fcc55a936502e8ba61ba041f52e (patch) | |
tree | 16701d6f7d12f0c9b5453c3f4701e97bf9ad7e64 /block | |
parent | 581c88153a829dbe8c24faea91311b1701be4b7e (diff) |
genirq: Deal with desc->set_type() changing desc->chip
commit 4673247562e39a17e09440fa1400819522ccd446 upstream.
The set_type() function can change the chip implementation when the
trigger mode changes. That might result in using an non-initialized
irq chip when called from __setup_irq() or when called via
set_irq_type() on an already enabled irq.
The set_irq_type() function should not be called on an enabled irq,
but because we forgot to put a check into it, we have a bunch of users
which grew the habit of doing that and it never blew up as the
function is serialized via desc->lock against all users of desc->chip
and they never hit the non-initialized irq chip issue.
The easy fix for the __setup_irq() issue would be to move the
irq_chip_set_defaults(desc->chip) call after the trigger setting to
make sure that a chip change is covered.
But as we have already users, which do the type setting after
request_irq(), the safe fix for now is to call irq_chip_set_defaults()
from __irq_set_trigger() when desc->set_type() changed the irq chip.
It needs a deeper analysis whether we should refuse to change the chip
on an already enabled irq, but that'd be a large scale change to fix
all the existing users. So that's neither stable nor 2.6.35 material.
Reported-by: Esben Haabendal <eha@doredevelopment.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev <linuxppc-dev@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'block')
0 files changed, 0 insertions, 0 deletions