VIDEO: amba clcd: don't disable an already disabled clock
Fix the clock enable/disable tracking in the AMBA CLCD driver so
that the driver doesn't try to disable an already disabled clock,
thereby causing the clock (if shared) to become unbalanced.
This resolves a problem with CLCD on LPC32xx ARM platforms.
Reported-by: Kevin Wells <wellsk40@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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 @@
/*
* 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 @@
/*
* 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..be33b3a 100644
--- a/include/linux/amba/clcd.h
+++ b/include/linux/amba/clcd.h
@@ -150,6 +150,7 @@
u16 off_cntl;
u32 clcd_cntl;
u32 cmap[16];
+ bool clk_enabled;
};
static inline void clcdfb_decode(struct clcd_fb *fb, struct clcd_regs *regs)