usb: gadget: Provide a default implementation of default manufacturer string

Some gadgets provide custom entry here. Some may override it with an
etntry that is also created by composite if there was no value sumbitted
at all.
This patch removes all "custom manufacturer" strings which are the same
as these which are created by composite. Then it moves the creation of
the default manufacturer string to usb_composite_overwrite_options() in
case no command line argument has been used and the entry is still an
empty string.
By doing this we get rid of the global variable "composite_manufacturer"
in composite.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 22 insertions, 45 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index f3689e1bf4b2..c7066cd4c95a 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -28,9 +28,6 @@
  * with the relevant device-wide data.
  */
 
-static char composite_manufacturer[50];
-
-/*-------------------------------------------------------------------------*/
 /**
  * next_ep_desc() - advance to the next EP descriptor
  * @t: currect pointer within descriptor array
@@ -860,7 +857,6 @@ static int get_string(struct usb_composite_dev *cdev,
 	struct usb_configuration	*c;
 	struct usb_function		*f;
 	int				len;
-	const char			*str;
 
 	/* Yes, not only is USB's I18N support probably more than most
 	 * folk will ever care about ... also, it's all supported here.
@@ -900,21 +896,6 @@ static int get_string(struct usb_composite_dev *cdev,
 		return s->bLength;
 	}
 
-	/* Otherwise, look up and return a specified string.  First
-	 * check if the string has not been overridden.
-	 */
-	if (cdev->manufacturer_override == id)
-		str = composite_manufacturer;
-	else
-		str = NULL;
-	if (str) {
-		struct usb_gadget_strings strings = {
-			.language = language,
-			.strings  = &(struct usb_string) { 0xff, str }
-		};
-		return usb_gadget_get_string(&strings, 0xff, buf);
-	}
-
 	/* String IDs are device-scoped, so we look up each string
 	 * table we're told about.  These lookups are infrequent;
 	 * simpler-is-better here.
@@ -1367,23 +1348,11 @@ composite_unbind(struct usb_gadget *gadget)
 		usb_ep_free_request(gadget->ep0, cdev->req);
 	}
 	device_remove_file(&gadget->dev, &dev_attr_suspended);
+	kfree(cdev->def_manufacturer);
 	kfree(cdev);
 	set_gadget_data(gadget, NULL);
 }
 
-static u8 override_id(struct usb_composite_dev *cdev, u8 *desc)
-{
-	if (!*desc) {
-		int ret = usb_string_id(cdev);
-		if (unlikely(ret < 0))
-			WARNING(cdev, "failed to override string ID\n");
-		else
-			*desc = ret;
-	}
-
-	return *desc;
-}
-
 static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
 		const struct usb_device_descriptor *old)
 {
@@ -1477,19 +1446,6 @@ static int composite_bind(struct usb_gadget *gadget,
 
 	update_unchanged_dev_desc(&cdev->desc, composite->dev);
 
-	/* string overrides */
-	if (!cdev->desc.iManufacturer) {
-		snprintf(composite_manufacturer,
-				sizeof composite_manufacturer,
-				"%s %s with %s",
-				init_utsname()->sysname,
-				init_utsname()->release,
-				gadget->name);
-
-		cdev->manufacturer_override =
-			override_id(cdev, &cdev->desc.iManufacturer);
-	}
-
 	/* has userspace failed to provide a serial number? */
 	if (composite->needs_serial && !cdev->desc.iSerialNumber)
 		WARNING(cdev, "userspace failed to provide iSerialNumber\n");
@@ -1665,6 +1621,22 @@ void usb_composite_setup_continue(struct usb_composite_dev *cdev)
 	spin_unlock_irqrestore(&cdev->lock, flags);
 }
 
+static char *composite_default_mfr(struct usb_gadget *gadget)
+{
+	char *mfr;
+	int len;
+
+	len = snprintf(NULL, 0, "%s %s with %s", init_utsname()->sysname,
+			init_utsname()->release, gadget->name);
+	len++;
+	mfr = kmalloc(len, GFP_KERNEL);
+	if (!mfr)
+		return NULL;
+	snprintf(mfr, len, "%s %s with %s", init_utsname()->sysname,
+			init_utsname()->release, gadget->name);
+	return mfr;
+}
+
 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
 		struct usb_composite_overwrite *covr)
 {
@@ -1688,6 +1660,11 @@ void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
 	if (covr->manufacturer) {
 		desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
 		dev_str[USB_GADGET_MANUFACTURER_IDX].s = covr->manufacturer;
+
+	} else if (!strlen(dev_str[USB_GADGET_MANUFACTURER_IDX].s)) {
+		desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
+		cdev->def_manufacturer = composite_default_mfr(cdev->gadget);
+		dev_str[USB_GADGET_MANUFACTURER_IDX].s = cdev->def_manufacturer;
 	}
 
 	if (covr->product) {