Patchwork sparc: Remove bogus of_set_property_mutex

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Submitter David Miller
Date Nov. 9, 2009, 1:41 a.m.
Message ID <20091108.174134.45234225.davem@davemloft.net>
Download mbox | patch
Permalink /patch/37955/
State Accepted
Delegated to: David Miller
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Comments

David Miller - Nov. 9, 2009, 1:41 a.m.
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 8 Nov 2009 21:16:47 +0100 (CET)

> Then you need to fix the problem that you lock the mutex inside the
> preempt disabled region under devtree_lock. :)

That's simple, just move it outside the rwlock:

sparc: Move of_set_property_mutex acquisition outside of devtree_lock grab.

Otherwise we try to sleep with preemption disabled, etc.

Noticed by Thomas Gleixner.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 arch/sparc/kernel/prom_common.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/sparc/kernel/prom_common.c b/arch/sparc/kernel/prom_common.c
index 138910c..d80a65d 100644
--- a/arch/sparc/kernel/prom_common.c
+++ b/arch/sparc/kernel/prom_common.c
@@ -79,6 +79,7 @@  int of_set_property(struct device_node *dp, const char *name, void *val, int len
 
 	err = -ENODEV;
 
+	mutex_lock(&of_set_property_mutex);
 	write_lock(&devtree_lock);
 	prevp = &dp->properties;
 	while (*prevp) {
@@ -88,9 +89,7 @@  int of_set_property(struct device_node *dp, const char *name, void *val, int len
 			void *old_val = prop->value;
 			int ret;
 
-			mutex_lock(&of_set_property_mutex);
 			ret = prom_setprop(dp->node, name, val, len);
-			mutex_unlock(&of_set_property_mutex);
 
 			err = -EINVAL;
 			if (ret >= 0) {
@@ -109,6 +108,7 @@  int of_set_property(struct device_node *dp, const char *name, void *val, int len
 		prevp = &(*prevp)->next;
 	}
 	write_unlock(&devtree_lock);
+	mutex_unlock(&of_set_property_mutex);
 
 	/* XXX Upate procfs if necessary... */