[v1,1/8] lib/string: introduce match_string() helper

Commit Message

Heikki Krogerus Jan. 7, 2016, 1:24 p.m. UTC

On Thu, Jan 07, 2016 at 03:12:00PM +0200, Andy Shevchenko wrote:
> On Thu, 2016-01-07 at 15:07 +0200, Heikki Krogerus wrote:
> > On Thu, Jan 07, 2016 at 02:06:01PM +0200, Andy Shevchenko wrote:
> > > > From time to time we have to match a string in an array. Make a
> > > > simple helper
> > > for that purpose.
> > 
> > Cool! If you make v2 out of these, could you patch the following
> > while
> > at it:
> 
> Yes, please, format as a usual patch and share with me. I will include
> in v3 (actually I missed the numbering here, it should be v2 already).

Sure thing. Here's the patch.

Patch

diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
index e6ec125..677b3f0 100644
--- a/drivers/usb/common/common.c
+++ b/drivers/usb/common/common.c
@@ -64,18 +64,15 @@  EXPORT_SYMBOL_GPL(usb_speed_string);
 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
 {
 	const char *maximum_speed;
-	int err;
-	int i;
+	int ret;
 
-	err = device_property_read_string(dev, "maximum-speed", &maximum_speed);
-	if (err < 0)
+	ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
+	if (ret < 0)
 		return USB_SPEED_UNKNOWN;
 
-	for (i = 0; i < ARRAY_SIZE(speed_names); i++)
-		if (strcmp(maximum_speed, speed_names[i]) == 0)
-			return i;
+	ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
 
-	return USB_SPEED_UNKNOWN;
+	return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
 }
 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
 
@@ -109,13 +106,10 @@  static const char *const usb_dr_modes[] = {
 
 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
 {
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
-		if (!strcmp(usb_dr_modes[i], str))
-			return i;
+	int ret;
 
-	return USB_DR_MODE_UNKNOWN;
+	ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
+	return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
 }
 
 enum usb_dr_mode usb_get_dr_mode(struct device *dev)