[PATCH] CLKDEV: Reduce scaning time

[PATCH] CLKDEV: Reduce scaning time

[Jonghwan Choi]

If ether dev_id or con_id is NULL. it is not necessary that match point should be 3.
it just takes a long time.

Signed-off-by: Jonghwan Choi <jhbird.choi@gmail.com>
---
 drivers/clk/clkdev.c |   14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 6db161f..d1fcb67 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -35,7 +35,13 @@ static DEFINE_MUTEX(clocks_mutex);
 static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
 {
 	struct clk_lookup *p, *cl = NULL;
-	int match, best = 0;
+	int match, best = 0, point = 0;
+
+	if (dev_id)
+		point += 2;
+
+	if (con_id)
+		point += 1;
 
 	list_for_each_entry(p, &clocks, node) {
 		match = 0;
@@ -52,10 +58,10 @@ static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
 
 		if (match > best) {
 			cl = p;
-			if (match != 3)
-				best = match;
-			else
+			if (match == point)
 				break;
+			else
+				best = match;
 		}
 	}
 	return cl;
-- 
1.7.0.4

[PATCH] CLKDEV: Reduce scaning time

[Russell King - ARM Linux]

On Fri, Sep 16, 2011 at 11:14:12PM +0900, Jonghwan Choi wrote:
> If ether dev_id or con_id is NULL. it is not necessary that match point
> should be 3.  it just takes a long time.

clk_get() shouldn't be used in fast paths anyway - drivers should 'get'
the clock and hold a reference to the clock while they're using it and
all the time that they're needing it to be enabled.

I think I'd like to keep the code as-is to discourage its use in fast
paths.  In any case:

> @@ -52,10 +58,10 @@ static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
>  
>  		if (match > best) {
>  			cl = p;
> -			if (match != 3)
> -				best = match;
> -			else
> +			if (match == point)
>  				break;
> +			else
> +				best = match;

Why not just change the '3' to be 'point' here - why restructure the code?