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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2013-11-14 17:38:05 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2013-11-14 17:38:05 -0800 |
| commit | 42249094f79422fbf5ed4b54eeb48ff096809b8f (patch) | |
| tree | 91e6850c8c7e8cc284cf8bb6363f8662f84011f4 /include/uapi/linux/usb | |
| parent | 936816161978ca716a56c5e553c68f25972b1e3a (diff) | |
| parent | 2c027b7c48a888ab173ba45babb4525e278375d9 (diff) | |
Merge branch 'next' into for-linus
Merge first round of changes for 3.13 merge window.
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 */ |