The usbfs interface does not provide any way for the user to learn the
speed at which a device is connected. The current API includes a
USBDEVFS_CONNECTINFO ioctl, but all it provides is the device's
address and a one-bit value indicating whether the connection is low
speed. That may have sufficed in the era of USB-1.1, but it isn't
good enough today.
This patch introduces a new ioctl, USBDEVFS_GET_SPEED, which returns a
numeric value indicating the speed of the connection: unknown, low,
full, high, wireless, super, or super-plus.
Similar information (not exactly the same) is available through sysfs,
but it seems reasonable to provide the actual value in usbfs.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Reinhard Huck <reinhard.huck@xxxxxxxxxxx>
---
[as1832]
drivers/usb/core/devio.c | 24 ++++++++++++++++++++++++
include/uapi/linux/usbdevice_fs.h | 10 ++++++++++
2 files changed, 34 insertions(+)
Index: usb-4.x/drivers/usb/core/devio.c
===================================================================
--- usb-4.x.orig/drivers/usb/core/devio.c
+++ usb-4.x/drivers/usb/core/devio.c
@@ -1322,6 +1322,27 @@ static int proc_connectinfo(struct usb_d
return 0;
}
+static int proc_get_speed(struct usb_dev_state *ps)
+{
+ switch (ps->dev->speed) {
+ case USB_SPEED_UNKNOWN:
+ return USBDEVFS_SPEED_UNKNOWN;
+ case USB_SPEED_LOW:
+ return USBDEVFS_SPEED_LOW;
+ case USB_SPEED_FULL:
+ return USBDEVFS_SPEED_FULL;
+ case USB_SPEED_HIGH:
+ return USBDEVFS_SPEED_HIGH;
+ case USB_SPEED_WIRELESS:
+ return USBDEVFS_SPEED_WIRELESS;
+ case USB_SPEED_SUPER:
+ return USBDEVFS_SPEED_SUPER;
+ case USB_SPEED_SUPER_PLUS:
+ return USBDEVFS_SPEED_SUPER_PLUS;
+ }
+ return -ERANGE;
+}
+
static int proc_resetdevice(struct usb_dev_state *ps)
{
struct usb_host_config *actconfig = ps->dev->actconfig;
@@ -2537,6 +2558,9 @@ static long usbdev_do_ioctl(struct file
case USBDEVFS_DROP_PRIVILEGES:
ret = proc_drop_privileges(ps, p);
break;
+ case USBDEVFS_GET_SPEED:
+ ret = proc_get_speed(ps);
+ break;
}
done:
Index: usb-4.x/include/uapi/linux/usbdevice_fs.h
===================================================================
--- usb-4.x.orig/include/uapi/linux/usbdevice_fs.h
+++ usb-4.x/include/uapi/linux/usbdevice_fs.h
@@ -156,6 +156,15 @@ struct usbdevfs_streams {
unsigned char eps[0];
};
+/* connection speed values used by USBDEVFS_GET_SPEED */
+#define USBDEVFS_SPEED_UNKNOWN 0
+#define USBDEVFS_SPEED_LOW 1
+#define USBDEVFS_SPEED_FULL 2
+#define USBDEVFS_SPEED_HIGH 3
+#define USBDEVFS_SPEED_WIRELESS 4
+#define USBDEVFS_SPEED_SUPER 5
+#define USBDEVFS_SPEED_SUPER_PLUS 6
+
#define USBDEVFS_CONTROL _IOWR('U', 0, struct usbdevfs_ctrltransfer)
#define USBDEVFS_CONTROL32 _IOWR('U', 0, struct usbdevfs_ctrltransfer32)
#define USBDEVFS_BULK _IOWR('U', 2, struct usbdevfs_bulktransfer)
@@ -190,5 +199,6 @@ struct usbdevfs_streams {
#define USBDEVFS_ALLOC_STREAMS _IOR('U', 28, struct usbdevfs_streams)
#define USBDEVFS_FREE_STREAMS _IOR('U', 29, struct usbdevfs_streams)
#define USBDEVFS_DROP_PRIVILEGES _IOW('U', 30, __u32)
+#define USBDEVFS_GET_SPEED _IO('U', 31)
#endif /* _UAPI_LINUX_USBDEVICE_FS_H */
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