diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-08-28 18:37:31 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-08-28 18:37:31 +0100 |
| commit | cdf0bfb0126bbd8c5424ca01fd59fd70d8ea80f9 (patch) | |
| tree | e7864d3dacf433b7ccbe17a49b2e72b6a4b3a24c /include/uapi/linux/usb | |
| parent | b4f656eea63376da79b0b5a17660c4ce14b71b74 (diff) | |
| parent | 6af396a6b6c698eb3834184518fc9a59bc22c817 (diff) | |
Merge branch 'for-rmk/barriers' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable
Diffstat (limited to 'include/uapi/linux/usb')
| -rw-r--r-- | include/uapi/linux/usb/ch11.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/uapi/linux/usb/ch11.h b/include/uapi/linux/usb/ch11.h index 7692dc69ccf7..331499d597fa 100644 --- a/include/uapi/linux/usb/ch11.h +++ b/include/uapi/linux/usb/ch11.h @@ -11,6 +11,17 @@ #include <linux/types.h> /* __u8 etc */ +/* This is arbitrary. + * From USB 2.0 spec Table 11-13, offset 7, a hub can + * have up to 255 ports. The most yet reported is 10. + * + * Current Wireless USB host hardware (Intel i1480 for example) allows + * up to 22 devices to connect. Upcoming hardware might raise that + * limit. Because the arrays need to add a bit for hub status data, we + * use 31, so plus one evens out to four bytes. + */ +#define USB_MAXCHILDREN 31 + /* * Hub request types */ |