diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2013-06-27 15:27:07 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-16 15:33:02 -0700 |
| commit | 36ff66db3fb5642906e46e73ca9cf92f1c5974ff (patch) | |
| tree | 69c6dfc6275116e073727d11d8f8febb4e71350a /include/uapi/linux/usb | |
| parent | 39c242704cba38bdf67566589facdd6fb2f2d941 (diff) | |
USB: move the definition of USB_MAXCHILDREN
The USB_MAXCHILDREN symbol is used in include/uapi/linux/usb/ch11.h, a
user-mode header, even though it is defined in include/linux/usb.h,
which is kernel-only. This causes compile-time errors when user
programs try to #include linux/usb/ch11.h.
This patch fixes the problem by moving the definition of USB_MAXCHILDREN
into ch11.h. It also gets rid of unneeded parentheses.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 */ |