Hi, evan@xxxxxxxxxxx writes: > 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 When this happens, I see this: modprobe-1046 [001] d..1 123.450054: dwc3_gadget_ep_cmd: ep0out: cmd 'Start New Configuration' [9] params 00000000 00000000 00000000 --> status: Successful modprobe-1046 [001] d..1 123.451990: dwc3_gadget_ep_cmd: ep0out: cmd 'Set Endpoint Transfer Resource' [2] params 00000001 00000000 00000000 --> status: Timed Out Why is that waiting only 1ms? Maybe your platform takes longer, sometimes, to complete xfer resource allocation? Try this: diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index d67655384eb2..ad1069fe3b8f 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -270,7 +270,7 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd, { const struct usb_endpoint_descriptor *desc = dep->endpoint.desc; struct dwc3 *dwc = dep->dwc; - u32 timeout = 1000; + u32 timeout = 5000; u32 saved_config = 0; u32 reg; Let me know if it helps or not. I guess it's also time to switch this block of code to readl_poll_timeout_atomic(). -- balbi
