ALSA: hda: Fix racy display power access

[sfrench/cifs-2.6.git] / sound / hda / hdac_component.c

diff --git a/sound/hda/hdac_component.c b/sound/hda/hdac_component.c
index a6d37b9d6413f51b49fd4486a251bf7e84261532..6b5caee61c6e024f059a74772028eceeef055e56 100644 (file)
--- a/sound/hda/hdac_component.c
+++ b/sound/hda/hdac_component.c
@@ -69,13 +69,15 @@ void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable)
 
        dev_dbg(bus->dev, "display power %s\n",
                enable ? "enable" : "disable");
+
+       mutex_lock(&bus->lock);
        if (enable)
                set_bit(idx, &bus->display_power_status);
        else
                clear_bit(idx, &bus->display_power_status);
 
        if (!acomp || !acomp->ops)
-               return;
+               goto unlock;
 
        if (bus->display_power_status) {
                if (!bus->display_power_active) {
@@ -92,6 +94,8 @@ void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable)
                        bus->display_power_active = false;
                }
        }
+ unlock:
+       mutex_unlock(&bus->lock);
 }
 EXPORT_SYMBOL_GPL(snd_hdac_display_power);