Documentation: usb: chipidea: Update test procedure for HNP polling
Update HNP test procedure as HNP polling is supported.
Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
diff --git a/Documentation/usb/chipidea.txt b/Documentation/usb/chipidea.txt
index 05f735a..678741b0 100644
--- a/Documentation/usb/chipidea.txt
+++ b/Documentation/usb/chipidea.txt
@@ -26,16 +26,17 @@
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,