RE: [PATCH v2] usb: host: xhci-plat: fix support for XHCI_SKIP_PHY_INIT quirk

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>]

> From: Pali Rohár, Sent: Tuesday, February 2, 2021 12:12 AM
> On Tuesday 26 January 2021 10:06:06 Pali Rohár wrote:
> > On Tuesday 26 January 2021 04:27:37 Yoshihiro Shimoda wrote:
> > > Hi Pali,
> > > > > I can see the benefit in this.
> > > > > In the xhci-plat case usb_create_hcd and usb_add_hcd are separate steps, and
> > > > > we could both copy the xhci_plat_priv .quirks and run the .init_qurks before
> > > > > adding the hcd.
> > > > > I guess the current way is inherited from pci case where the earliest place
> > > > > to do this after hcd is created is the hcd->driver->reset callback (which is
> > > > > set to xhci_pci_setup() or xhci_plat_setup()).
> > > > >
> > > > > xhci-rcar.c is using the .init_quirk to load firmware, we need to check with
> > > > > them if this change is ok. (added Yoshihiro Shimoda to cc)
> > > >
> > > > Yoshihiro, is this change OK?
> > > >
> > > > Can we move forward? I really need to now how to handle regression in
> > > > xhci-mvebu driver. And one option is with this patch...
> > >
> > > Thank you for asking me about this topic. I tested the patch, but unfortunately,
> > > this patch is possible to break a rcar platform because a phy initialization is
> > > needed before the firmware loading if the platform uses the phy. (Note that
> > > upstream code (salvator-common.dtsi) doesn't use the phy for xhci. But,
> > > if we use the phy on other board with this patch, the xhci will not work.)
> > >
> > > So, I think we need to add a new function pointer for your case.
> >
> > Ok, thank you for testing! I will try to come up with other solution to
> > mentioned mvebu-xhci issue.
> 
> Hello! New version of this patch is in following thread, please review it:
> "[PATCH v2] usb: host: xhci: mvebu: make USB 3.0 PHY optional for Armada 3720"

Thanks! I'll review it.

Best regards,
Yoshihiro Shimoda