drivers/video/backlight/l4f00242t03.c: prevent unbalanced calls to regulator enable/disable

Otherwise a double call to:
$ echo 4 > /sys/class/lcd/l4f00242t03/lcd_power
Will, the first power down the lcd and regulators correctly and the
second produce an unbalanced call to regulator disable.

Signed-off-by: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/video/backlight/l4f00242t03.c b/drivers/video/backlight/l4f00242t03.c
index 5d25743bf8e2..1fcaaf3d78e1 100644
--- a/drivers/video/backlight/l4f00242t03.c
+++ b/drivers/video/backlight/l4f00242t03.c
@@ -134,10 +134,12 @@ static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
                 }
         } else {
                 /* power == FB_BLANK_POWERDOWN */
-                /* Clear the screen before shutting down */
-                spi_write(spi, (const u8 *)&disoff, sizeof(u16));
-                msleep(60);
-                l4f00242t03_lcd_powerdown(spi);
+                if (priv->lcd_state != FB_BLANK_POWERDOWN) {
+                        /* Clear the screen before shutting down */
+                        spi_write(spi, (const u8 *)&disoff, sizeof(u16));
+                        msleep(60);
+                        l4f00242t03_lcd_powerdown(spi);
+                }
         }
 
         priv->lcd_state = power;