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
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
