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Message-Id: <201108220818.48725.rjw@sisk.pl>
Date: Mon, 22 Aug 2011 08:18:48 +0200
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: linux-sh@...r.kernel.org
Cc: Linux PM mailing list <linux-pm@...ts.linux-foundation.org>,
LKML <linux-kernel@...r.kernel.org>,
Magnus Damm <magnus.damm@...il.com>,
Alan Stern <stern@...land.harvard.edu>
Subject: [Replacement][PATCH 1/2 v2] PM: Use spinlock instead of mutex in clock management functions
From: Rafael J. Wysocki <rjw@...k.pl>
The lock member of struct pm_clk_data is of type struct mutex,
which is a problem, because the suspend and resume routines
defined in drivers/base/power/clock_ops.c cannot be executed
with interrupts disabled for this reason. Modify
struct pm_clk_data so that its lock member is a spinlock.
Signed-off-by: Rafael J. Wysocki <rjw@...k.pl>
---
The previous [1/2] in this series was on top of the branch at
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git pm-domains
but what is needed now is a version on top of the current mainline tree, which
is this one.
Thanks,
Rafael
---
drivers/base/power/clock_ops.c | 40 ++++++++++++++++++++++------------------
1 file changed, 22 insertions(+), 18 deletions(-)
Index: linux/drivers/base/power/clock_ops.c
===================================================================
--- linux.orig/drivers/base/power/clock_ops.c
+++ linux/drivers/base/power/clock_ops.c
@@ -19,7 +19,7 @@
struct pm_clk_data {
struct list_head clock_list;
- struct mutex lock;
+ spinlock_t lock;
};
enum pce_status {
@@ -73,9 +73,9 @@ int pm_clk_add(struct device *dev, const
}
}
- mutex_lock(&pcd->lock);
+ spin_lock_irq(&pcd->lock);
list_add_tail(&ce->node, &pcd->clock_list);
- mutex_unlock(&pcd->lock);
+ spin_unlock_irq(&pcd->lock);
return 0;
}
@@ -83,8 +83,8 @@ int pm_clk_add(struct device *dev, const
* __pm_clk_remove - Destroy PM clock entry.
* @ce: PM clock entry to destroy.
*
- * This routine must be called under the mutex protecting the PM list of clocks
- * corresponding the the @ce's device.
+ * This routine must be called under the spinlock protecting the PM list of
+ * clocks corresponding the the @ce's device.
*/
static void __pm_clk_remove(struct pm_clock_entry *ce)
{
@@ -123,7 +123,7 @@ void pm_clk_remove(struct device *dev, c
if (!pcd)
return;
- mutex_lock(&pcd->lock);
+ spin_lock_irq(&pcd->lock);
list_for_each_entry(ce, &pcd->clock_list, node) {
if (!con_id && !ce->con_id) {
@@ -137,7 +137,7 @@ void pm_clk_remove(struct device *dev, c
}
}
- mutex_unlock(&pcd->lock);
+ spin_unlock_irq(&pcd->lock);
}
/**
@@ -158,7 +158,7 @@ int pm_clk_init(struct device *dev)
}
INIT_LIST_HEAD(&pcd->clock_list);
- mutex_init(&pcd->lock);
+ spin_lock_init(&pcd->lock);
dev->power.subsys_data = pcd;
return 0;
}
@@ -181,12 +181,12 @@ void pm_clk_destroy(struct device *dev)
dev->power.subsys_data = NULL;
- mutex_lock(&pcd->lock);
+ spin_lock_irq(&pcd->lock);
list_for_each_entry_safe_reverse(ce, c, &pcd->clock_list, node)
__pm_clk_remove(ce);
- mutex_unlock(&pcd->lock);
+ spin_unlock_irq(&pcd->lock);
kfree(pcd);
}
@@ -220,13 +220,14 @@ int pm_clk_suspend(struct device *dev)
{
struct pm_clk_data *pcd = __to_pcd(dev);
struct pm_clock_entry *ce;
+ unsigned long flags;
dev_dbg(dev, "%s()\n", __func__);
if (!pcd)
return 0;
- mutex_lock(&pcd->lock);
+ spin_lock_irqsave(&pcd->lock, flags);
list_for_each_entry_reverse(ce, &pcd->clock_list, node) {
if (ce->status == PCE_STATUS_NONE)
@@ -238,7 +239,7 @@ int pm_clk_suspend(struct device *dev)
}
}
- mutex_unlock(&pcd->lock);
+ spin_unlock_irqrestore(&pcd->lock, flags);
return 0;
}
@@ -251,13 +252,14 @@ int pm_clk_resume(struct device *dev)
{
struct pm_clk_data *pcd = __to_pcd(dev);
struct pm_clock_entry *ce;
+ unsigned long flags;
dev_dbg(dev, "%s()\n", __func__);
if (!pcd)
return 0;
- mutex_lock(&pcd->lock);
+ spin_lock_irqsave(&pcd->lock, flags);
list_for_each_entry(ce, &pcd->clock_list, node) {
if (ce->status == PCE_STATUS_NONE)
@@ -269,7 +271,7 @@ int pm_clk_resume(struct device *dev)
}
}
- mutex_unlock(&pcd->lock);
+ spin_unlock_irqrestore(&pcd->lock, flags);
return 0;
}
@@ -344,6 +346,7 @@ int pm_clk_suspend(struct device *dev)
{
struct pm_clk_data *pcd = __to_pcd(dev);
struct pm_clock_entry *ce;
+ unsigned long flags;
dev_dbg(dev, "%s()\n", __func__);
@@ -351,12 +354,12 @@ int pm_clk_suspend(struct device *dev)
if (!pcd || !dev->driver)
return 0;
- mutex_lock(&pcd->lock);
+ spin_lock_irqsave(&pcd->lock, flags);
list_for_each_entry_reverse(ce, &pcd->clock_list, node)
clk_disable(ce->clk);
- mutex_unlock(&pcd->lock);
+ spin_unlock_irqrestore(&pcd->lock, flags);
return 0;
}
@@ -369,6 +372,7 @@ int pm_clk_resume(struct device *dev)
{
struct pm_clk_data *pcd = __to_pcd(dev);
struct pm_clock_entry *ce;
+ unsigned long flags;
dev_dbg(dev, "%s()\n", __func__);
@@ -376,12 +380,12 @@ int pm_clk_resume(struct device *dev)
if (!pcd || !dev->driver)
return 0;
- mutex_lock(&pcd->lock);
+ spin_lock_irqsave(&pcd->lock, flags);
list_for_each_entry(ce, &pcd->clock_list, node)
clk_enable(ce->clk);
- mutex_unlock(&pcd->lock);
+ spin_unlock_irqrestore(&pcd->lock, flags);
return 0;
}
--
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