[PATCH] usbcore: Fix handling of sysfs strings and other attributes
This patch (as592) makes a few small improvements to the way device
strings are handled, and it fixes some bugs in a couple of other sysfs
attribute routines. (Look at show_configuration_string() to see what I
mean.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 63f374e6..9930195 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -112,8 +112,12 @@
struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
int j;
- for (j = 0; j < intfc->num_altsetting; j++)
- kfree(intfc->altsetting[j].endpoint);
+ for (j = 0; j < intfc->num_altsetting; j++) {
+ struct usb_host_interface *alt = &intfc->altsetting[j];
+
+ kfree(alt->endpoint);
+ kfree(alt->string);
+ }
kfree(intfc);
}
@@ -420,8 +424,6 @@
struct usb_host_config *cf = &dev->config[c];
kfree(cf->string);
- cf->string = NULL;
-
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/hub.c b/drivers/usb/core/hub.c
index 8ba5854..1bacb37 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1204,21 +1204,6 @@
{}
#endif
-static void get_string(struct usb_device *udev, char **string, int index)
-{
- char *buf;
-
- if (!index)
- return;
- buf = kmalloc(256, GFP_KERNEL);
- if (!buf)
- return;
- if (usb_string(udev, index, buf, 256) > 0)
- *string = buf;
- else
- kfree(buf);
-}
-
#ifdef CONFIG_USB_OTG
#include "otg_whitelist.h"
@@ -1257,9 +1242,10 @@
}
/* read the standard strings and cache them if present */
- get_string(udev, &udev->product, udev->descriptor.iProduct);
- get_string(udev, &udev->manufacturer, udev->descriptor.iManufacturer);
- get_string(udev, &udev->serial, udev->descriptor.iSerialNumber);
+ udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
+ udev->manufacturer = usb_cache_string(udev,
+ udev->descriptor.iManufacturer);
+ udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
/* Tell the world! */
dev_dbg(&udev->dev, "new device strings: Mfr=%d, Product=%d, "
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 3519f31..644a3d4 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -787,6 +787,31 @@
return err;
}
+/**
+ * usb_cache_string - read a string descriptor and cache it for later use
+ * @udev: the device whose string descriptor is being read
+ * @index: the descriptor index
+ *
+ * Returns a pointer to a kmalloc'ed buffer containing the descriptor string,
+ * or NULL if the index is 0 or the string could not be read.
+ */
+char *usb_cache_string(struct usb_device *udev, int index)
+{
+ char *buf;
+ char *smallbuf = NULL;
+ int len;
+
+ if (index > 0 && (buf = kmalloc(256, GFP_KERNEL)) != NULL) {
+ if ((len = usb_string(udev, index, buf, 256)) > 0) {
+ if ((smallbuf = kmalloc(++len, GFP_KERNEL)) == NULL)
+ return buf;
+ memcpy(smallbuf, buf, len);
+ }
+ kfree(buf);
+ }
+ return smallbuf;
+}
+
/*
* usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
* @dev: the device whose device descriptor is being updated
@@ -1008,8 +1033,6 @@
dev_dbg (&dev->dev, "unregistering interface %s\n",
interface->dev.bus_id);
usb_remove_sysfs_intf_files(interface);
- kfree(interface->cur_altsetting->string);
- interface->cur_altsetting->string = NULL;
device_del (&interface->dev);
}
@@ -1422,12 +1445,9 @@
}
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);
- }
+ if (cp->string == NULL)
+ cp->string = usb_cache_string(dev,
+ cp->desc.iConfiguration);
/* Now that all the interfaces are set up, register them
* to trigger binding of drivers to interfaces. probe()
@@ -1437,13 +1457,12 @@
*/
for (i = 0; i < nintf; ++i) {
struct usb_interface *intf = cp->interface[i];
- struct usb_interface_descriptor *desc;
+ struct usb_host_interface *alt = intf->cur_altsetting;
- desc = &intf->altsetting [0].desc;
dev_dbg (&dev->dev,
"adding %s (config #%d, interface %d)\n",
intf->dev.bus_id, configuration,
- desc->bInterfaceNumber);
+ alt->desc.bInterfaceNumber);
ret = device_add (&intf->dev);
if (ret != 0) {
dev_err(&dev->dev,
@@ -1452,13 +1471,6 @@
ret);
continue;
}
- if ((intf->cur_altsetting->desc.iInterface) &&
- (intf->cur_altsetting->string == NULL)) {
- intf->cur_altsetting->string = kmalloc(256, GFP_KERNEL);
- if (intf->cur_altsetting->string)
- usb_string(dev, intf->cur_altsetting->desc.iInterface,
- intf->cur_altsetting->string, 256);
- }
usb_create_sysfs_intf_files (intf);
}
}
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 4cca77c..edd83e0 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -249,18 +249,12 @@
{
struct usb_device *udev;
struct usb_host_config *actconfig;
- int len;
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;
+ return sprintf(buf, "%s\n", actconfig->string);
}
static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);
@@ -291,15 +285,9 @@
struct device_attribute *attr, char *buf) \
{ \
struct usb_device *udev; \
- int len; \
\
udev = to_usb_device (dev); \
- len = snprintf(buf, 256, "%s", udev->name); \
- if (len < 0) \
- return 0; \
- buf[len] = '\n'; \
- buf[len+1] = 0; \
- return len+1; \
+ return sprintf(buf, "%s\n", udev->name); \
} \
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
@@ -449,11 +437,11 @@
usb_remove_ep_files(&udev->ep0);
sysfs_remove_group(&dev->kobj, &dev_attr_grp);
- if (udev->descriptor.iManufacturer)
+ if (udev->manufacturer)
device_remove_file(dev, &dev_attr_manufacturer);
- if (udev->descriptor.iProduct)
+ if (udev->product)
device_remove_file(dev, &dev_attr_product);
- if (udev->descriptor.iSerialNumber)
+ if (udev->serial)
device_remove_file(dev, &dev_attr_serial);
device_remove_file (dev, &dev_attr_configuration);
}
@@ -535,7 +523,8 @@
.attrs = intf_attrs,
};
-static inline void usb_create_intf_ep_files(struct usb_interface *intf)
+static inline void usb_create_intf_ep_files(struct usb_interface *intf,
+ struct usb_device *udev)
{
struct usb_host_interface *iface_desc;
int i;
@@ -543,7 +532,7 @@
iface_desc = intf->cur_altsetting;
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i)
usb_create_ep_files(&intf->dev.kobj, &iface_desc->endpoint[i],
- interface_to_usbdev(intf));
+ udev);
}
static inline void usb_remove_intf_ep_files(struct usb_interface *intf)
@@ -558,11 +547,16 @@
void usb_create_sysfs_intf_files (struct usb_interface *intf)
{
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct usb_host_interface *alt = intf->cur_altsetting;
+
sysfs_create_group(&intf->dev.kobj, &intf_attr_grp);
- if (intf->cur_altsetting->string)
+ if (alt->string == NULL)
+ alt->string = usb_cache_string(udev, alt->desc.iInterface);
+ if (alt->string)
device_create_file(&intf->dev, &dev_attr_interface);
- usb_create_intf_ep_files(intf);
+ usb_create_intf_ep_files(intf, udev);
}
void usb_remove_sysfs_intf_files (struct usb_interface *intf)
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 888dbe4..1c4a684 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -13,6 +13,7 @@
extern int usb_get_device_descriptor(struct usb_device *dev,
unsigned int size);
+extern char *usb_cache_string(struct usb_device *udev, int index);
extern int usb_set_configuration(struct usb_device *dev, int configuration);
extern void usb_lock_all_devices(void);
diff --git a/include/linux/usb.h b/include/linux/usb.h
index c500d6b..748d043 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -231,7 +231,7 @@
struct usb_host_config {
struct usb_config_descriptor desc;
- char *string;
+ char *string; /* iConfiguration string, if present */
/* the interfaces associated with this configuration,
* stored in no particular order */
struct usb_interface *interface[USB_MAXINTERFACES];
@@ -351,9 +351,11 @@
int have_langid; /* whether string_langid is valid */
int string_langid; /* language ID for strings */
- char *product;
- char *manufacturer;
- char *serial; /* static strings from the device */
+ /* static strings from the device */
+ char *product; /* iProduct string, if present */
+ char *manufacturer; /* iManufacturer string, if present */
+ char *serial; /* iSerialNumber string, if present */
+
struct list_head filelist;
struct class_device *class_dev;
struct dentry *usbfs_dentry; /* usbfs dentry entry for the device */