ChangeSet 1.1474.148.18, 2004/01/26 17:12:05-08:00, stern@rowland.harvard.edu
[PATCH] USB: Fix DMA coherence when reading device descriptor
drivers/usb/core/hub.c | 5 +++--
drivers/usb/core/message.c | 37 ++++++++++++++++++++++++-------------
drivers/usb/core/usb.c | 6 +++---
drivers/usb/core/usb.h | 3 +++
include/linux/usb.h | 1 -
5 files changed, 33 insertions(+), 19 deletions(-)
diff -Nru a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
--- a/drivers/usb/core/hub.c Tue Jan 27 15:12:40 2004
+++ b/drivers/usb/core/hub.c Tue Jan 27 15:12:40 2004
@@ -31,6 +31,7 @@
#include <asm/uaccess.h>
#include <asm/byteorder.h>
+#include "usb.h"
#include "hcd.h"
#include "hub.h"
@@ -1316,8 +1317,8 @@
kfree(descriptor);
usb_destroy_configuration(dev);
- ret = usb_get_device_descriptor(dev);
- if (ret < sizeof(dev->descriptor)) {
+ ret = usb_get_device_descriptor(dev, sizeof(dev->descriptor));
+ if (ret != sizeof(dev->descriptor)) {
if (ret < 0)
err("unable to get device %s descriptor "
"(error=%d)", dev->devpath, ret);
diff -Nru a/drivers/usb/core/message.c b/drivers/usb/core/message.c
--- a/drivers/usb/core/message.c Tue Jan 27 15:12:40 2004
+++ b/drivers/usb/core/message.c Tue Jan 27 15:12:40 2004
@@ -546,10 +546,10 @@
*
* Gets a USB descriptor. Convenience functions exist to simplify
* getting some types of descriptors. Use
- * usb_get_device_descriptor() for USB_DT_DEVICE,
+ * usb_get_device_descriptor() for USB_DT_DEVICE (not exported),
* and usb_get_string() or usb_string() for USB_DT_STRING.
- * Configuration descriptors (USB_DT_CONFIG) are part of the device
- * structure, at least for the current configuration.
+ * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
+ * are part of the device structure.
* In addition to a number of USB-standard descriptors, some
* devices also use class-specific or vendor-specific descriptors.
*
@@ -610,6 +610,7 @@
/**
* usb_get_device_descriptor - (re)reads the device descriptor
* @dev: the device whose device descriptor is being updated
+ * @size: how much of the descriptor to read
* Context: !in_interrupt ()
*
* Updates the copy of the device descriptor stored in the device structure,
@@ -618,24 +619,35 @@
* vendors product and version fields (idVendor, idProduct, and bcdDevice).
* That lets device drivers compare against non-byteswapped constants.
*
- * There's normally no need to use this call, although some devices
- * will change their descriptors after events like updating firmware.
+ * Not exported, only for use by the core. If drivers really want to read
+ * the device descriptor directly, they can call usb_get_descriptor() with
+ * type = USB_DT_DEVICE and index = 0.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Returns the number of bytes received on success, or else the status code
* returned by the underlying usb_control_msg() call.
*/
-int usb_get_device_descriptor(struct usb_device *dev)
+int usb_get_device_descriptor(struct usb_device *dev, unsigned int size)
{
- int ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor,
- sizeof(dev->descriptor));
+ struct usb_device_descriptor *desc;
+ int ret;
+
+ if (size > sizeof(*desc))
+ return -EINVAL;
+ desc = kmalloc(sizeof(*desc), GFP_NOIO);
+ if (!desc)
+ return -ENOMEM;
+
+ ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size);
if (ret >= 0) {
- le16_to_cpus(&dev->descriptor.bcdUSB);
- le16_to_cpus(&dev->descriptor.idVendor);
- le16_to_cpus(&dev->descriptor.idProduct);
- le16_to_cpus(&dev->descriptor.bcdDevice);
+ le16_to_cpus(&desc->bcdUSB);
+ le16_to_cpus(&desc->idVendor);
+ le16_to_cpus(&desc->idProduct);
+ le16_to_cpus(&desc->bcdDevice);
+ memcpy(&dev->descriptor, desc, size);
}
+ kfree(desc);
return ret;
}
@@ -1241,7 +1253,6 @@
// synchronous control message convenience routines
EXPORT_SYMBOL(usb_get_descriptor);
-EXPORT_SYMBOL(usb_get_device_descriptor);
EXPORT_SYMBOL(usb_get_status);
EXPORT_SYMBOL(usb_get_string);
EXPORT_SYMBOL(usb_string);
diff -Nru a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
--- a/drivers/usb/core/usb.c Tue Jan 27 15:12:40 2004
+++ b/drivers/usb/core/usb.c Tue Jan 27 15:12:40 2004
@@ -1065,7 +1065,7 @@
wait_ms(10); /* Let the SET_ADDRESS settle */
/* high and low speed devices don't need this... */
- err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor, 8);
+ err = usb_get_device_descriptor(dev, 8);
if (err >= 8)
break;
wait_ms(100);
@@ -1085,8 +1085,8 @@
/* USB device state == addressed ... still not usable */
- err = usb_get_device_descriptor(dev);
- if (err < (signed)sizeof(dev->descriptor)) {
+ err = usb_get_device_descriptor(dev, sizeof(dev->descriptor));
+ if (err != (signed)sizeof(dev->descriptor)) {
dev_err(&dev->dev, "device descriptor read/all, error %d\n", err);
goto fail;
}
diff -Nru a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
--- a/drivers/usb/core/usb.h Tue Jan 27 15:12:40 2004
+++ b/drivers/usb/core/usb.h Tue Jan 27 15:12:40 2004
@@ -14,3 +14,6 @@
struct usb_endpoint_descriptor *epd);
extern void usb_enable_interface (struct usb_device *dev,
struct usb_interface *intf);
+
+extern int usb_get_device_descriptor(struct usb_device *dev,
+ unsigned int size);
diff -Nru a/include/linux/usb.h b/include/linux/usb.h
--- a/include/linux/usb.h Tue Jan 27 15:12:40 2004
+++ b/include/linux/usb.h Tue Jan 27 15:12:40 2004
@@ -856,7 +856,6 @@
/* wrappers around usb_control_msg() for the most common standard requests */
extern int usb_get_descriptor(struct usb_device *dev, unsigned char desctype,
unsigned char descindex, void *buf, int size);
-extern int usb_get_device_descriptor(struct usb_device *dev);
extern int usb_get_status(struct usb_device *dev,
int type, int target, void *data);
extern int usb_get_string(struct usb_device *dev,