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| author | Jiri Kosina <jkosina@suse.cz> | 2013-09-04 12:49:39 +0400 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2013-09-04 12:49:57 +0400 |
| commit | efd15f5f4ff63f6ac5d80850686e3d2cc8c4481b (patch) | |
| tree | 40024adbe77a3d660662e639fd765097133d648c /include/uapi/linux/usb/ch11.h | |
| parent | 6c2794a2984f4c17a58117a68703cc7640f01c5a (diff) | |
| parent | 58c59bc997d86593f0bea41845885917cf304d22 (diff) | |
| download | linux-efd15f5f4ff63f6ac5d80850686e3d2cc8c4481b.tar.xz | |
Merge branch 'master' into for-3.12/upstream
Sync with Linus' tree to be able to apply fixup patch on top
of 9d9a04ee75 ("HID: apple: Add support for the 2013 Macbook Air")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'include/uapi/linux/usb/ch11.h')
| -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 */ |