Bus error when testing Tx2 USB 2.0 singal

Hello

I tried to follow “Jetson_TX2_TX2i_USB2_Tuning_Guide_Application_Note” to test usb2 signal.

But I always get Bus error when I get register XUSB_XHCI_OP_USBSTS_0

Below is log.

root@master:/sys/bus/usb/devices/usb1# cat /sys/bus/usb/devices/usb1/power/control
on
root@master:/sys/bus/usb/devices/usb1# devmem2 0x3530460 w
/dev/mem opened.
Memory mapped at address 0x7fa7a0f000.
Value at address 0x3530460 (0x7fa7a0f460): 0xE03
root@master:/sys/bus/usb/devices/usb1# devmem2 0x3530460 w 0xc03
/dev/mem opened.
Memory mapped at address 0x7fa783a000.
Value at address 0x3530460 (0x7fa783a460): 0xE03
Written 0xC03; readback 0xE03
root@master:/sys/bus/usb/devices/usb1# devmem2 0x3530460 w
/dev/mem opened.
Memory mapped at address 0x7f95222000.
Value at address 0x3530460 (0x7f95222460): 0x80
root@master:/sys/bus/usb/devices/usb1# devmem2 0x3530020 w
/dev/mem opened.
Memory mapped at address 0x7f9d21c000.
Value at address 0x3530020 (0x7f9d21c020): 0x805
root@master:/sys/bus/usb/devices/usb1# devmem2 0x3530020 w 0x804
/dev/mem opened.
Memory mapped at address 0x7f89135000.
Value at address 0x3530020 (0x7f89135020): 0x805
Written 0x804; readback 0x804
root@master:/sys/bus/usb/devices/usb1# devmem2 0x3530024 w
/dev/mem opened.
Memory mapped at address 0x7f8476a000.
Bus error
root@master:/sys/bus/usb/devices/usb1#

Do I have any error for this test?

Ho do I solve this problem?

Thanks!

Is the no 8bytes alignment address trigger the bus error?

Please try

root@tegra-ubuntu:/home/nvidia# devmem2 0x3530024 b
/dev/mem opened.
Memory mapped at address 0x7fb46ea000.
Value at address 0x3530024 (0x7fb46ea024): 0x1
root@tegra-ubuntu:/home/nvidia# devmem2 0x3530024 h
/dev/mem opened.
Memory mapped at address 0x7f91c05000.
Value at address 0x3530024 (0x7f91c05024): 0x1

Hi DaneLLL

Thanks for your your reply!

Issue is solved.

Root cause is 8bytes access with 4bytes alignment address.