Re: [PATCH 4/6] usb: cdns3: support power-off of controller when in host role

[Peter Chen <peter.chen@kernel.org>]

On 23-11-14 12:10:18, Théo Lebrun wrote:
> Hello,
> 
> On Tue Nov 14, 2023 at 9:38 AM CET, Peter Chen wrote:
> > On 23-11-13 15:26:59, Théo Lebrun wrote:
> > > The controller is not being reconfigured at resume. Change resume to
> > > redo hardware config if quirk CDNS3_RESET_ON_RESUME is active.
> >
> > Current logic has power off judgement, see cdns3_controller_resume for
> > detail.
> 
> Indeed! Thanks for the pointer. I had not noticed that, those patches
> come from an older kernel which didn't have it. That'll make for less
> changes; patches 4 & 5 can go away.
> 
> > > +	if (cdns->pdata && cdns->pdata->quirks & CDNS3_RESET_ON_RESUME)
> > > +		cdns->xhci_plat_data->quirks |= XHCI_RESET_ON_RESUME | XHCI_SUSPEND_RESUME_CLKS;
> > > +
> >
> > If you set this flag, how could you support the USB remote wakeup
> > request? In that case, the USB bus does not expect re-enumeration.
> 
> We didn't support remote USB wakeup. Only S2R mattered in our case and
> USB remote wakeup wasn't a possibility.

Without this patch, will below be hit for your platform:


	/* re-initialize the HC on Restore Error, or Host Controller Error */
	if (temp & (STS_SRE | STS_HCE)) {
		reinit_xhc = true;
		if (!xhci->broken_suspend)
			xhci_warn(xhci, "xHC error in resume, USBSTS 0x%x, Reinit\n", temp);
	}


-- 

Thanks,
Peter Chen