[PATCH 3.16 189/357] ARM: imx: fix .is_enabled() of shared gate clock

[Greg Kroah-Hartman]

3.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Shawn Guo <shawn.guo@xxxxxxxxxxxxx>

commit 9e1ac462b982f496ed3b491f02c417dcc8e40347 upstream.

Commit 63288b721a80 ("ARM: imx: fix shared gate clock") attempted to fix
an issue with particular enable/disable sequence from two shared gate
clocks.  But unfortunately, while it partially fixed the issue, it also
did something wrong in .is_enabled() function hook.  In case of shared
gate, the function shouldn't really query the hardware state via
share_count, because the function is trying to query the enabling state
of the clock in question, not the hardware state which is shared by
multiple clocks.

Fix the issue by returning the enable_count of the clock itself which is
maintained by clock core, in case it's a clock sharing hardware gate
with others.  As the result, the initialization of share_count per
hardware state is not needed now.  So remove it.

Reported-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
Fixes: 63288b721a80 ("ARM: imx: fix shared gate clock")
Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxxxxx>
Tested-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
Signed-off-by: Olof Johansson <olof@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/arm/mach-imx/clk-gate2.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/arch/arm/mach-imx/clk-gate2.c
+++ b/arch/arm/mach-imx/clk-gate2.c
@@ -97,7 +97,7 @@ static int clk_gate2_is_enabled(struct c
 	struct clk_gate2 *gate = to_clk_gate2(hw);
 
 	if (gate->share_count)
-		return !!(*gate->share_count);
+		return !!__clk_get_enable_count(hw->clk);
 	else
 		return clk_gate2_reg_is_enabled(gate->reg, gate->bit_idx);
 }
@@ -127,10 +127,6 @@ struct clk *clk_register_gate2(struct de
 	gate->bit_idx = bit_idx;
 	gate->flags = clk_gate2_flags;
 	gate->lock = lock;
-
-	/* Initialize share_count per hardware state */
-	if (share_count)
-		*share_count = clk_gate2_reg_is_enabled(reg, bit_idx) ? 1 : 0;
 	gate->share_count = share_count;
 
 	init.name = name;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/