RE: [PATCH] usb: host: xhci-rcar: Avoid long wait in xhci_reset()

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Hi Felipe,

> From: Felipe Balbi
> Sent: Thursday, April 21, 2016 7:19 PM
> 
> Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> writes:
> 
> > Hi Felipe,
> >
> >> From: Felipe Balbi
> >> Sent: Thursday, April 21, 2016 7:05 PM
> >>
> >> Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> writes:
> >>
> >> > If kernel configuration is CONFIG_USB_XHCI_PLATFORM=y and
> >> > CONFIG_USB_XHCI_RCAR is not set, R-Car Gen2/3 will cause long wait
> >> > in xhci_reset() because such SoCs need specific initialization.
> >>
> >> where is the delay coming from exactly ?
> >
> > The delay is coming from the following code:
> >
> > 	ret = xhci_handshake(&xhci->op_regs->command,
> > 			CMD_RESET, 0, 10 * 1000 * 1000);
> > 	if (ret)
> > 		return ret;
> 
> okay, and why does reset fail ?

Oops, I don't know why. So, I will investigate it.

> > And, kernel log is the following:
> >
> > [    1.565605] xhci-hcd ee000000.usb: xHCI Host Controller
> > [    1.570636] xhci-hcd ee000000.usb: new USB bus registered, assigned bus number 5
> > [   22.270160] xhci-hcd ee000000.usb: can't setup: -110
> > [   22.274931] xhci-hcd ee000000.usb: USB bus 5 deregistered
> > [   22.280158] xhci-hcd: probe of ee000000.usb failed with error -110
> >
> > The timestamp is strange to me. But, logs of R-Car H3 (ES1.0) and
> > R-Car H2 were the same.
> 
> yeah, seems like your system timer is counting twice for each tick.

Yes, I will investigate this later.

> > Should I revise the commit log in detail?
> 
> Sure, but let's first why this is the case. It's unclear, to me at
> least, why reset fails.

I understood it. I will investigate why reset fails first.

Best regards,
Yoshihiro Shimoda

> --
> balbi
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