From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Wed, 18 Apr 2012 22:16:48 +0000 (+0000)
Subject: powerpc/pmac: Don't add_timer() twice
X-Git-Tag: v3.4-rc5~43^2~3
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3027691e58bfb21f6ea2e9f1d225d11b4e2b20e2;p=pandora-kernel.git

powerpc/pmac: Don't add_timer() twice

If the interrupt and the timeout happen roughly at the same
time, we can get into a situation where the timer function
is run while the interrupt has already been processed. In
this case, the timer function might end up doing an add_timer
on an already pending timer, causing a BUG_ON() to trigger.

Instead, just skip the whole timeout operation if we see that
the timer is pending. The spinlock ensures that the only way
that happens is if we already started a new operation and thus
the timeout can be ignored.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

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