Hi Felipe, I'm picking up a bug my coworker Rob touched on in this thread: https://marc.info/?l=linux-usb&m=155349928622570&w=2
We occasionally see the following dmesg when enabling mass storage mode:
dwc3 dwc3.1.auto: failed to enable ep0out
To reproduce after a clean boot:
Enable mass storage mode
Disable mass storage mode
Enable mass storage mode
I don't need to plug any devices, just switch modes.
The error does not happen every boot. If I don't get the error on that
second enable, then as far as I can tell I won't get the error at all
during that boot.
I've attached the trace and regdump. When capturing these I was running
a 4.9.115 kernel and using the g_mass_storage driver for simplicity.
Here is the shell session:
root@gnarbox-2:~# echo device >
/sys/class/usb_role/intel_xhci_usb_sw-role-switch/role && modprobe
g_mass_storage file=/dev/nvme0n1p7 iSerialNumber=90405
[ 118.627628] Mass Storage Function, version: 2009/09/11
[ 118.633426] LUN: removable file: (no medium)
[ 118.638283] LUN: file: /dev/nvme0n1p7
[ 118.642397] Number of LUNs=1
[ 118.646080] g_mass_storage gadget: Mass Storage Gadget, version:
2009/09/11
[ 118.653902] g_mass_storage gadget: g_mass_storage ready
root@gnarbox-2:~# modprobe -r g_mass_storage && echo host >
/sys/class/usb_role/intel_xhci_usb_sw-role-switch/role
root@gnarbox-2:~# echo device >
/sys/class/usb_role/intel_xhci_usb_sw-role-switch/role && modprobe
g_mass_storage file=/dev/nvme0n1p7 iSerialNumber=90405
[ 123.416789] Mass Storage Function, version: 2009/09/11
[ 123.422546] LUN: removable file: (no medium)
[ 123.427386] LUN: file: /dev/nvme0n1p7
[ 123.431531] Number of LUNs=1
[ 123.435278] g_mass_storage gadget: Mass Storage Gadget, version:
2009/09/11
[ 123.443168] g_mass_storage gadget: g_mass_storage ready
[ 123.451998] dwc3 dwc3.1.auto: failed to enable ep0out
root@gnarbox-2:~#
I still get the error when using the gadget configfs instead of
g_mass_storage. I still get the error on kernel 5.0.5.
Do you have any idea what's happening here? What steps can I take to
help debug this?
Thanks,
Evan
dwc3-trace-20190513.txz
Description: application/xz
