Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

[linux-2.6-block.git] / Documentation / usb / chipidea.txt

diff --git a/Documentation/usb/chipidea.txt b/Documentation/usb/chipidea.txt
index 05f735a1b5a574cb73875e64275480ae63f83b40..678741b0f213e5e93b7c7930a6f9b307300de3ac 100644 (file)
--- a/Documentation/usb/chipidea.txt
+++ b/Documentation/usb/chipidea.txt
@@ -26,16 +26,17 @@ cat /sys/kernel/debug/ci_hdrc.0/registers
    On B-device:
    echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
 
-   if HNP polling is not supported, also need:
-   On A-device:
-   echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
-
    B-device should take host role and enumrate A-device.
 
 4) A-device switch back to host.
    On B-device:
    echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
 
+   or, by introducing HNP polling, B-Host can know when A-peripheral wish
+   to be host role, so this role switch also can be trigged in A-peripheral
+   side by answering the polling from B-Host, this can be done on A-device:
+   echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
+
    A-device should switch back to host and enumrate B-device.
 
 5) Remove B-device(unplug micro B plug) and insert again in 10 seconds,