[PATCH] USB: cache the iConfiguration string, if present.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 30 insertions, 20 deletions

diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 42e9f8466272..837bad132449 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -420,6 +420,9 @@ void usb_destroy_configuration(struct usb_device *dev)
 	for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 		struct usb_host_config *cf = &dev->config[c];
 
+		if (cf->string)
+			kfree(cf->string);
+
 		for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 			if (cf->intf_cache[i])
 				kref_put(&cf->intf_cache[i]->ref, 
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index f6b2c309e55d..b4624501cd58 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1413,6 +1413,13 @@ free_interfaces:
 		}
 		kfree(new_interfaces);
 
+		if ((cp->desc.iConfiguration) &&
+		    (cp->string == NULL)) {
+			cp->string = kmalloc(256, GFP_KERNEL);
+			if (cp->string)
+				usb_string(dev, cp->desc.iConfiguration, cp->string, 256);
+		}
+
 		/* Now that all the interfaces are set up, register them
 		 * to trigger binding of drivers to interfaces.  probe()
 		 * routines may install different altsettings and may
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 3f5ae2de70e2..ec9b3bde8ae5 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -46,27 +46,24 @@ usb_actconfig_attr (bNumInterfaces, 1, "%2d\n")
 usb_actconfig_attr (bmAttributes, 1, "%2x\n")
 usb_actconfig_attr (bMaxPower, 2, "%3dmA\n")
 
-#define usb_actconfig_str(name, field)					\
-static ssize_t  show_##name(struct device *dev, char *buf)		\
-{									\
-	struct usb_device *udev;					\
-	struct usb_host_config *actconfig;				\
-	int len;							\
-									\
-	udev = to_usb_device (dev);					\
-	actconfig = udev->actconfig;					\
-	if (!actconfig)							\
-		return 0;						\
-	len = usb_string(udev, actconfig->desc.field, buf, PAGE_SIZE);	\
-	if (len < 0)							\
-		return 0;						\
-	buf[len] = '\n';						\
-	buf[len+1] = 0;							\
-	return len+1;							\
-}									\
-static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
+static ssize_t show_configuration_string(struct device *dev, char *buf)
+{
+	struct usb_device *udev;
+	struct usb_host_config *actconfig;
+	int len;
 
-usb_actconfig_str (configuration, iConfiguration)
+	udev = to_usb_device (dev);
+	actconfig = udev->actconfig;
+	if ((!actconfig) || (!actconfig->string))
+		return 0;
+	len = sprintf(buf, actconfig->string, PAGE_SIZE);
+	if (len < 0)
+		return 0;
+	buf[len] = '\n';
+	buf[len+1] = 0;
+	return len+1;
+}
+static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);
 
 /* configuration value is always present, and r/w */
 usb_actconfig_show(bConfigurationValue, 1, "%u\n");
diff --git a/include/linux/usb.h b/include/linux/usb.h
index f5ec1f5d8920..8d2687ae39ff 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -190,6 +190,8 @@ struct usb_interface_cache {
 /**
  * struct usb_host_config - representation of a device's configuration
  * @desc: the device's configuration descriptor.
+ * @string: pointer to the cached version of the iConfiguration string, if
+ *	present for this configuration.
  * @interface: array of pointers to usb_interface structures, one for each
  *	interface in the configuration.  The number of interfaces is stored
  *	in desc.bNumInterfaces.  These pointers are valid only while the
@@ -226,6 +228,7 @@ struct usb_interface_cache {
 struct usb_host_config {
 	struct usb_config_descriptor	desc;
 
+	char *string;
 	/* the interfaces associated with this configuration,
 	 * stored in no particular order */
 	struct usb_interface *interface[USB_MAXINTERFACES];