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| author | Sage Weil <sage@inktank.com> | 2013-08-15 11:11:45 -0700 |
|---|---|---|
| committer | Sage Weil <sage@inktank.com> | 2013-08-15 11:11:45 -0700 |
| commit | ee3e542fec6e69bc9fb668698889a37d93950ddf (patch) | |
| tree | e74ee766a4764769ef1d3d45d266b4dea64101d3 /include/uapi/linux/usb/ch11.h | |
| parent | fe2a801b50c0bb8039d627e5ae1fec249d10ff39 (diff) | |
| parent | f1d6e17f540af37bb1891480143669ba7636c4cf (diff) | |
Merge remote-tracking branch 'linus/master' into testing
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 7692dc69ccf..331499d597f 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 */ |