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| author | Mark Brown <broonie@linaro.org> | 2013-08-22 11:09:03 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@linaro.org> | 2013-08-22 11:09:03 +0100 |
| commit | 64393c6e647c8a791243063d282c787b46721be7 (patch) | |
| tree | 89ca12bd5d52e8df24d2bc13a36d30479a4e825d /include/uapi/linux/usb | |
| parent | a2388a498ad2f85be01aca29e364abf427d9b53c (diff) | |
| parent | 741a509f34d8d702f70d0ad99b8152c57d76961e (diff) | |
Merge remote-tracking branch 'asoc/topic/ac97' into asoc-fsl
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 */ |