ARM: tegra: dvfs: Add lock to dvfs_reg

Change-Id: I0496cf37da3a20d697eb4f372c32d01d49352f98
Signed-off-by: Colin Cross <ccross@android.com>

diff --git a/arch/arm/mach-tegra/dvfs.c b/arch/arm/mach-tegra/dvfs.c
index 82a10f80696f857bdf5e5c1681ca20c1210ff938..ef58fae8afbd1cef2ce138046c49987da5c1a72d 100644 (file)
--- a/arch/arm/mach-tegra/dvfs.c
+++ b/arch/arm/mach-tegra/dvfs.c
@@ -40,6 +40,7 @@ struct dvfs_reg {
        struct regulator *reg;
        int max_millivolts;
        int millivolts;
+       struct mutex lock;
 };
 
 static LIST_HEAD(dvfs_debug_list);
@@ -52,22 +53,29 @@ static int dvfs_reg_set_voltage(struct dvfs_reg *dvfs_reg)
 {
        int millivolts = 0;
        struct dvfs *d;
+       int ret = 0;
+
+       mutex_lock(&dvfs_reg->lock);
 
        list_for_each_entry(d, &dvfs_reg->dvfs, reg_node)
                millivolts = max(d->cur_millivolts, millivolts);
 
        if (millivolts == dvfs_reg->millivolts)
-               return 0;
+               goto out;
 
        dvfs_reg->millivolts = millivolts;
 
        if (!dvfs_reg->reg) {
                pr_warn("dvfs set voltage on %s ignored\n", dvfs_reg->reg_id);
-               return 0;
+               goto out;
        }
 
-       return regulator_set_voltage(dvfs_reg->reg,
+       ret = regulator_set_voltage(dvfs_reg->reg,
                millivolts * 1000, dvfs_reg->max_millivolts * 1000);
+
+out:
+       mutex_unlock(&dvfs_reg->lock);
+       return ret;
 }
 
 static int dvfs_reg_connect_to_regulator(struct dvfs_reg *dvfs_reg)
@@ -101,6 +109,7 @@ static struct dvfs_reg *get_dvfs_reg(struct dvfs *d)
                goto out;
        }
 
+       mutex_init(&dvfs_reg->lock);
        INIT_LIST_HEAD(&dvfs_reg->dvfs);
        dvfs_reg->reg_id = kstrdup(d->reg_id, GFP_KERNEL);
 
@@ -119,12 +128,15 @@ static struct dvfs_reg *attach_dvfs_reg(struct dvfs *d)
        if (!dvfs_reg)
                return NULL;
 
+       mutex_lock(&dvfs_reg->lock);
        list_add_tail(&d->reg_node, &dvfs_reg->dvfs);
+
        d->dvfs_reg = dvfs_reg;
        if (d->max_millivolts > d->dvfs_reg->max_millivolts)
                d->dvfs_reg->max_millivolts = d->max_millivolts;
 
        d->cur_millivolts = d->max_millivolts;
+       mutex_unlock(&dvfs_reg->lock);
 
        return dvfs_reg;
 }