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| author | Chris Zankel <chris@zankel.net> | 2013-09-05 17:12:08 -0700 |
|---|---|---|
| committer | Chris Zankel <chris@zankel.net> | 2013-09-05 17:12:08 -0700 |
| commit | 0bc2ba94a65d2cd2ad01004d2d3f94f31c6064bd (patch) | |
| tree | fc0354e4da0ff5ab8b8eb65d60d9a8359d02634d /include/uapi/linux/usb | |
| parent | 3b2f64d00c46e1e4e9bd0bb9bb12619adac27a4b (diff) | |
| parent | 6e4664525b1db28f8c4e1130957f70a94c19213e (diff) | |
Merge tag 'v3.11' into for_next
Update Xtensa tree to Linux 3.11 (merging)
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 */ |