[PATCH 1/8] ARM: OMAP2+: PM: protect the power domain state change by a mutex

[Jean Pihet]

omap_set_pwrdm_state is intented to be the only API for changing
a power domain state.
This patch protects the power domains settings and structs from
concurrent accesses to the function by using a mutex.

Signed-off-by: Jean Pihet <j-pihet at ti.com>
---
 arch/arm/mach-omap2/pm.c          |    8 ++++++--
 arch/arm/mach-omap2/powerdomain.c |    1 +
 arch/arm/mach-omap2/powerdomain.h |    3 ++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
index 9cb5ced..a05f00c 100644
--- a/arch/arm/mach-omap2/pm.c
+++ b/arch/arm/mach-omap2/pm.c
@@ -100,15 +100,17 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 pwrst)
 	if (!pwrdm || IS_ERR(pwrdm))
 		return -EINVAL;
 
+	mutex_lock(&pwrdm->lock);
+
 	while (!(pwrdm->pwrsts & (1 << pwrst))) {
 		if (pwrst == PWRDM_POWER_OFF)
-			return ret;
+			goto out;
 		pwrst--;
 	}
 
 	next_pwrst = pwrdm_read_next_pwrst(pwrdm);
 	if (next_pwrst == pwrst)
-		return ret;
+		goto out;
 
 	curr_pwrst = pwrdm_read_pwrst(pwrdm);
 	if (curr_pwrst < PWRDM_POWER_ON) {
@@ -141,6 +143,8 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 pwrst)
 		break;
 	}
 
+out:
+	mutex_unlock(&pwrdm->lock);
 	return ret;
 }
 
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index 9611490..1641e72 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -102,6 +102,7 @@ static int _pwrdm_register(struct powerdomain *pwrdm)
 	INIT_LIST_HEAD(&pwrdm->voltdm_node);
 	voltdm_add_pwrdm(voltdm, pwrdm);
 
+	mutex_init(&pwrdm->lock);
 	list_add(&pwrdm->node, &pwrdm_list);
 
 	/* Initialize the powerdomain's state counter */
diff --git a/arch/arm/mach-omap2/powerdomain.h b/arch/arm/mach-omap2/powerdomain.h
index 8f88d65..bab84fc 100644
--- a/arch/arm/mach-omap2/powerdomain.h
+++ b/arch/arm/mach-omap2/powerdomain.h
@@ -19,7 +19,7 @@
 
 #include <linux/types.h>
 #include <linux/list.h>
-
+#include <linux/mutex.h>
 #include <linux/atomic.h>
 
 #include <plat/cpu.h>
@@ -116,6 +116,7 @@ struct powerdomain {
 	struct clockdomain *pwrdm_clkdms[PWRDM_MAX_CLKDMS];
 	struct list_head node;
 	struct list_head voltdm_node;
+	struct mutex lock;
 	int state;
 	unsigned state_counter[PWRDM_MAX_PWRSTS];
 	unsigned ret_logic_off_counter;
-- 
1.7.7.6