[PATCH 1/2] video: amba_clcd: Fix driver clock enable/disable balance issues

[wellsk40 at gmail.com]

From: Kevin Wells <wellsk40 at gmail.com>

The amba clcd clock enable and disable calls can become unbalanced.
This usually occurs on the first call to clcdfb_set_par() during
LCD init, but can also occur when the LCD enters and exits blank
state. This fix prevents clk_disable() from being called until
clk_enable() has been called first.

Signed-off-by: Kevin Wells <wellsk40 at gmail.com>
---
 drivers/video/amba-clcd.c |   10 ++++++++--
 include/linux/amba/clcd.h |    1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/video/amba-clcd.c b/drivers/video/amba-clcd.c
index afe21e6..1c2c683 100644
--- a/drivers/video/amba-clcd.c
+++ b/drivers/video/amba-clcd.c
@@ -80,7 +80,10 @@ static void clcdfb_disable(struct clcd_fb *fb)
 	/*
 	 * Disable CLCD clock source.
 	 */
-	clk_disable(fb->clk);
+	if (fb->clk_enabled) {
+		fb->clk_enabled = false;
+		clk_disable(fb->clk);
+	}
 }
 
 static void clcdfb_enable(struct clcd_fb *fb, u32 cntl)
@@ -88,7 +91,10 @@ static void clcdfb_enable(struct clcd_fb *fb, u32 cntl)
 	/*
 	 * Enable the CLCD clock source.
 	 */
-	clk_enable(fb->clk);
+	if (!fb->clk_enabled) {
+		fb->clk_enabled = true;
+		clk_enable(fb->clk);
+	}
 
 	/*
 	 * Bring up by first enabling..
diff --git a/include/linux/amba/clcd.h b/include/linux/amba/clcd.h
index ca16c38..7bbf26a 100644
--- a/include/linux/amba/clcd.h
+++ b/include/linux/amba/clcd.h
@@ -142,6 +142,7 @@ struct clcd_fb {
 	struct fb_info		fb;
 	struct amba_device	*dev;
 	struct clk		*clk;
+	bool			clk_enabled;
 	struct clcd_panel	*panel;
 	struct clcd_board	*board;
 	void			*board_data;
-- 
1.7.1.1