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authorThomas Gleixner <tglx@linutronix.de>2013-08-21 14:44:54 +0200
committerThomas Gleixner <tglx@linutronix.de>2013-08-21 14:44:54 +0200
commitfac778a2b8d6ca953d440baeee72901c2dd5aad9 (patch)
treec43d780b5ff8819f4353b16c99601c5ceeeacad7 /include/uapi/linux/usb
parent07862c1cd6675cde2dd4bd64e64d704ea2185b79 (diff)
parent94fc5d9de5bd757ad46f0d94bc4ebf617c4487f6 (diff)
Merge branch 'linus' into timers/core
Reason: Get upstream changes on which new patches depend on. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/uapi/linux/usb')
-rw-r--r--include/uapi/linux/usb/ch11.h11
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
*/