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From: Jiri Slaby <jslaby@suse.cz>
To: Boris Ostrovsky <boris.ostrovsky@amd.com>
Cc: Len Brown <len.brown@intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	the arch/x86 maintainers <x86@kernel.org>,
	Jiri Slaby <jirislaby@gmail.com>
Subject: BUG at cpuidle_play_dead
Date: Thu, 05 Apr 2012 23:03:00 +0200	[thread overview]
Message-ID: <4F7E0884.5090602@suse.cz> (raw)

Hi,

I'm hitting this BUG as the last thing during shutdown:
BUG: unable to handle kernel NULL pointer dereference at 00000000000002d8
IP: [<ffffffff814ab60d>] cpuidle_play_dead+0x1d/0xb0


It's because drv is NULL. The problem is gone if I do this:
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -83,6 +83,11 @@ int cpuidle_play_dead(void)
        int i, dead_state = -1;
        int power_usage = -1;

+       if (!drv) {
+               printk("DRIVER IS NULL\n");
+               return -ENODEV;
+       }
+
        /* Find lowest-power state that supports long-term idle */
        for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
                struct cpuidle_state *s = &drv->states[i];

thanks,
-- 
js
suse labs


             reply	other threads:[~2012-04-05 21:03 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-05 21:03 Jiri Slaby [this message]
2012-04-05 21:11 ` BUG at cpuidle_play_dead Boris Ostrovsky

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