[PATCH] input: replace spin_lock_bh with spin_lock_irqsave in ml_ff_playback

From: Arjan van de Ven
Date: Sun Nov 23 2008 - 19:57:36 EST


ml_ff_playback() uses spin_(un)lock_bh. However this function is called
with interrupts disabled from erase_effect() in drivers/input/ff-core.c:196.

This is not permitted, and will result in a WARN_ON in the bottom half handling code.
This patch changes this function to just use spin_lock_irqsave() instead, solving
the problem and simplifying the locking logic.

This was reported as entry #106559 in kerneloops.org

Reported-by: kerneloops.org
Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
---
drivers/input/ff-memless.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c
index 6790e97..bc4e40f 100644
--- a/drivers/input/ff-memless.c
+++ b/drivers/input/ff-memless.c
@@ -397,8 +397,9 @@ static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
{
struct ml_device *ml = dev->ff->private;
struct ml_effect_state *state = &ml->states[effect_id];
+ unsigned long flags;

- spin_lock_bh(&ml->timer_lock);
+ spin_lock_irqsave(&ml->timer_lock, flags);

if (value > 0) {
debug("initiated play");
@@ -424,7 +425,7 @@ static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
ml_play_effects(ml);
}

- spin_unlock_bh(&ml->timer_lock);
+ spin_unlock_irqrestore(&ml->timer_lock, flags);

return 0;
}
--
1.6.0.3


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Arjan van de Ven Intel Open Source Technology Centre
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