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author | Grant Likely <grant.likely@linaro.org> | 2013-08-28 23:18:13 +0400 |
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committer | Grant Likely <grant.likely@linaro.org> | 2013-08-28 23:18:13 +0400 |
commit | 8be137f2664f0abb096626a9d2ce0fcdd955b109 (patch) | |
tree | 2c53a5535265a58eb397d6fbbab2ec26e92e6931 /include/uapi/linux/usb/ch11.h | |
parent | 8851b9f1625ce0858e9b1bb0ae4a57d4b43178b1 (diff) | |
parent | d8dfad3876e4386666b759da3c833d62fb8b2267 (diff) | |
download | linux-8be137f2664f0abb096626a9d2ce0fcdd955b109.tar.xz |
Merge tag 'v3.11-rc7' into devicetree/next
Linux 3.11-rc7
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 */ |