drm/panel/s6e3ha2: add locking to brightness update

Brightness update can be called asynchronously, so access to device should
be synchronized. To do this callback should be split into backlight callback
and device specific part, which can be called from other places.

Change-Id: Ib0c9d81ccaffe63b650dcd948c3ca1e770d03763
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>

diff --git a/drivers/gpu/drm/panel/panel-s6e3ha2.c b/drivers/gpu/drm/panel/panel-s6e3ha2.c
index 3d6683e..cf11128 100644 (file)
--- a/drivers/gpu/drm/panel/panel-s6e3ha2.c
+++ b/drivers/gpu/drm/panel/panel-s6e3ha2.c
@@ -532,37 +532,49 @@ static void s6e3ha2_update_gamma(struct s6e3ha2 *ctx, unsigned int brightness)
                ctx->bl_dev->props.brightness = brightness;
 }
 
-static int s6e3ha2_set_brightness(struct backlight_device *bl_dev)
+static void s6e3ha2_set_brightness(struct s6e3ha2 *ctx)
+{
+       s6e3ha2_test_key_on_f0(ctx);
+       s6e3ha2_update_gamma(ctx, ctx->bl_dev->props.brightness);
+       s6e3ha2_aor_control(ctx);
+       s6e3ha2_set_vint(ctx);
+       s6e3ha2_test_key_off_f0(ctx);
+}
+
+static int s6e3ha2_bl_update_status(struct backlight_device *bl_dev)
 {
        struct s6e3ha2 *ctx = (struct s6e3ha2 *)bl_get_data(bl_dev);
        unsigned int brightness = bl_dev->props.brightness;
        int ret;
 
+       mutex_lock(&ctx->lock);
+
        if (brightness < MIN_BRIGHTNESS ||
                brightness > bl_dev->props.max_brightness) {
                dev_err(ctx->dev, "Invalid brightness: %u\n", brightness);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto end;
        }
 
        if (bl_dev->props.power > FB_BLANK_NORMAL) {
                dev_err(ctx->dev,
                        "panel must be at least in fb blank normal state\n");
-               return -EPERM;
+               ret = -EPERM;
+               goto end;
        }
 
-       s6e3ha2_test_key_on_f0(ctx);
-       s6e3ha2_update_gamma(ctx, brightness);
-       s6e3ha2_aor_control(ctx);
-       s6e3ha2_set_vint(ctx);
+       s6e3ha2_set_brightness(ctx);
+       ret = s6e3ha2_clear_error(ctx);
 
-       s6e3ha2_test_key_off_f0(ctx);
+end:
+       mutex_unlock(&ctx->lock);
 
-       return 0;
+       return ret;
 }
 
 static const struct backlight_ops s6e3ha2_bl_ops = {
        .get_brightness = s6e3ha2_get_brightness,
-       .update_status = s6e3ha2_set_brightness,
+       .update_status = s6e3ha2_bl_update_status,
 };
 
 static void s6e3ha2_panel_init(struct s6e3ha2 *ctx)
@@ -715,7 +727,7 @@ static int s6e3ha2_enable(struct drm_panel *panel)
 
 
        /* brightness setting */
-       s6e3ha2_set_brightness(ctx->bl_dev);
+       s6e3ha2_set_brightness(ctx);
        s6e3ha2_aor_control(ctx);
        s6e3ha2_caps_elvss_set(ctx);
        s6e3ha2_gamma_update(ctx);