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Date:   Wed, 16 Feb 2022 13:30:28 +0530
From:   Pavan Kondeti <quic_pkondeti@quicinc.com>
To:     Jun Li <lijun.kernel@gmail.com>
CC:     Sandeep Maheswaram <quic_c_sanm@quicinc.com>,
        Peter Chen <peter.chen@kernel.org>,
        Pawel Laszczak <pawell@cadence.com>,
        Roger Quadros <rogerq@kernel.org>,
        Aswath Govindraju <a-govindraju@ti.com>,
        "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
        Felipe Balbi <balbi@kernel.org>,
        Mathias Nyman <mathias.nyman@intel.com>,
        Stephen Boyd <swboyd@chromium.org>,
        Doug Anderson <dianders@chromium.org>,
        Matthias Kaehlcke <mka@chromium.org>,
        <linux-arm-msm@vger.kernel.org>,
        Linux USB List <linux-usb@vger.kernel.org>,
        lkml <linux-kernel@vger.kernel.org>, <quic_pkondeti@quicinc.com>,
        <quic_ppratap@quicinc.com>
Subject: Re: [PATCH 2/2] usb: dwc: host: add xhci_plat_priv quirk
 XHCI_SKIP_PHY_INIT
Message-ID: <20220216080028.GA13793@hu-pkondeti-hyd.qualcomm.com>
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On Wed, Feb 16, 2022 at 03:16:40PM +0800, Jun Li wrote:
> Sandeep Maheswaram <quic_c_sanm@quicinc.com> 于2022年2月16日周三 14:58写道：
> >
> > dwc3 manages PHY by own DRD driver, so skip the management by
> > HCD core.
> > During runtime suspend phy was not getting suspend because
> > runtime_usage value is 2.
> >
> > Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> > ---
> >  drivers/usb/dwc3/host.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> >
> > diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> > index eda8719..4a035a8 100644
> > --- a/drivers/usb/dwc3/host.c
> > +++ b/drivers/usb/dwc3/host.c
> > @@ -13,6 +13,14 @@
> >  #include <linux/platform_device.h>
> >
> >  #include "core.h"
> > +#include <linux/usb/hcd.h>
> > +#include <linux/usb/xhci-plat.h>
> > +#include <linux/usb/xhci-quirks.h>
> > +
> > +
> > +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> > +       .quirks = XHCI_SKIP_PHY_INIT,
> > +};
> 
> It's better to create this xhci_plat_priv by each dwc3 glue layer,
> with that, we can use this priv to pass other flags and possibly
> override APIs by each glue driver which may not apply to all dwc3
> platforms.
> 

Do you see a need for any glue driver to know about this xHC platform data?
AFAICT, glue driver has no direction connection with the dwc3 core. All
the required data is coming from dT on ARM based boards. Adding a private
interface between dwc3 core and glue for passing xhci platform data seems
to be overkill. If there is a pressing need, why not?

Thanks,
Pavan