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Not to be fixed

LIN6-3663 : xilinx-zynq: usb otg issue

Created: May 24, 2013    Updated: Feb 23, 2018
Resolved Date: Feb 22, 2018
Previous ID: LIN5-4867, LIN6-2949
Found In Version: 6.0
Severity: Critical
Applicable for: Wind River Linux 6
Component/s: BSP - Async


1. hot plug udisk need to rewrite a_bus_req
# cd /sys/devices/amba.0/e0002000.usb/xusbps-otg.0/inputs/
# echo 1 > a_bus_req

2. otg can't switch from host mode to gadget mode, either fix it in code or document it.

3. below calltrace appeared if hotplug  udisk.
root@localhost:/sys/devices/amba.0/e0002000.usb/xusbps-otg.0/inpuxusbps-otg xusbps-otg.0: SRP detected or User has requested for the Bus
ts# xusbps-ehci xusbps-ehci.0: Xilinx PS USB EHCI Host Controller
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = 80004000
[00000000] *pgd=00000000
Internal error: Oops: 17 [#1] PREEMPT SMP ARM

Steps to Reproduce

1. boot board with cgl kernel, then set the jumper to enable usb work as otg mode
2. switch otg to host mode, and hotplug udisk

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