diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-29 07:43:16 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-29 07:43:16 -0700 |
| commit | 78283dd29e647775cb1e63a4d6554b3090b9a9ff (patch) | |
| tree | 46a179781ed356c0546379ecc46ca5daed7ae50a /include/uapi/linux | |
| parent | 435932f2c75efcdd07273a437b9be32647d56d73 (diff) | |
| parent | 5ae90d8e467e625e447000cb4335c4db973b1095 (diff) | |
Merge 3.11-rc3 into usb-next
Diffstat (limited to 'include/uapi/linux')
| -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 */ |