[PATCH] gianfar: Do not call device_set_wakeup_enable() under a spinlock

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From: Daniel J Blueman
Date: Monday, November 1, 2010 - 5:25 pm

Since device_set_wakeup_enable now sleeps, it should not be called
from a critical section. Since wol_en is not updated elsewhere, we can
omit the locking entirely.

Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>

diff --git a/drivers/net/gianfar_ethtool.c b/drivers/net/gianfar_ethtool.c
index 5c566eb..e641d7c 100644
--- a/drivers/net/gianfar_ethtool.c
+++ b/drivers/net/gianfar_ethtool.c
@@ -635,10 +635,8 @@ static int gfar_set_wol(struct net_device *dev,
struct ethtool_wolinfo *wol)
 	if (wol->wolopts & ~WAKE_MAGIC)
 		return -EINVAL;

-	spin_lock_irqsave(&priv->bflock, flags);
 	priv->wol_en = wol->wolopts & WAKE_MAGIC ? 1 : 0;
 	device_set_wakeup_enable(&dev->dev, priv->wol_en);
-	spin_unlock_irqrestore(&priv->bflock, flags);

 	return 0;
 }
-- 
Daniel J Blueman
--

From: Rafael J. Wysocki
Date: Monday, November 8, 2010 - 4:30 pm

From: Rafael J. Wysocki
Date: Tuesday, November 9, 2010 - 2:54 pm

Having reconsidered that I think it may be better to do something like in the
patch below.

This is a regression fix, so please apply if there are no objections.

Thanks,
Rafael

---
From: Rafael J. Wysocki <rjw@sisk.pl>
Subject: gianfar: Do not call device_set_wakeup_enable() under a spinlock

The gianfar driver calls device_set_wakeup_enable() under a spinlock,
which causes a problem to happen after the recent core power
management changes, because this function can sleep now.  Fix this
by moving the device_set_wakeup_enable() call out of the
spinlock-protected area.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/net/gianfar_ethtool.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/net/gianfar_ethtool.c
===================================================================
--- linux-2.6.orig/drivers/net/gianfar_ethtool.c
+++ linux-2.6/drivers/net/gianfar_ethtool.c
@@ -635,9 +635,10 @@ static int gfar_set_wol(struct net_devic
 	if (wol->wolopts & ~WAKE_MAGIC)
 		return -EINVAL;
 
+	device_set_wakeup_enable(&dev->dev, wol->wolopts & WAKE_MAGIC);
+
 	spin_lock_irqsave(&priv->bflock, flags);
-	priv->wol_en = wol->wolopts & WAKE_MAGIC ? 1 : 0;
-	device_set_wakeup_enable(&dev->dev, priv->wol_en);
+	priv->wol_en =  !!device_may_wakeup(&dev->dev);
 	spin_unlock_irqrestore(&priv->bflock, flags);
 
 	return 0;
--

From: David Miller
Date: Friday, November 12, 2010 - 3:06 pm

From: "Rafael J. Wysocki" <rjw@sisk.pl>

Patch applied, thank you.
--

Previous thread: [PATCH v3 0/2] usb: generic Kconfig fixes by Felipe Contreras on Monday, November 1, 2010 - 5:14 pm. (15 messages)

Next thread: [tip:core/locking] x86, mem: Don't implement forward memmove() as memcpy() by tip-bot for Ma, Ling on Monday, November 1, 2010 - 5:45 pm. (1 message)