RE: [EXT] Re: [PATCH v7 4/5] usb: host: Stops USB controller init if PLL fails to lock

[Yinbo Zhu <yinbo.zhu@nxp.com>]

> -----Original Message-----
> From: Greg Kroah-Hartman [mailto:gregkh@linuxfoundation.org]
> Sent: 2019年6月20日 20:10
> To: Yinbo Zhu <yinbo.zhu@nxp.com>
> Cc: Alan Stern <stern@rowland.harvard.edu>; Xiaobo Xie <xiaobo.xie@nxp.com>;
> Jiafei Pan <jiafei.pan@nxp.com>; Ramneek Mehresh
> <ramneek.mehresh@freescale.com>; Nikhil Badola
> <nikhil.badola@freescale.com>; Ran Wang <ran.wang_1@nxp.com>;
> linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: [EXT] Re: [PATCH v7 4/5] usb: host: Stops USB controller init if PLL fails to
> lock
> 
> Caution: EXT Email
> 
> On Fri, Jun 14, 2019 at 04:54:32PM +0800, Yinbo Zhu wrote:
> > From: Ramneek Mehresh <ramneek.mehresh@freescale.com>
> >
> > USB erratum-A006918 workaround tries to start internal PHY inside
> > uboot (when PLL fails to lock). However, if the workaround also fails,
> > then USB initialization is also stopped inside Linux.
> > Erratum-A006918 workaround failure creates "fsl,erratum_a006918"
> > node in device-tree. Presence of this node in device-tree is used to
> > stop USB controller initialization in Linux
> >
> > Signed-off-by: Ramneek Mehresh <ramneek.mehresh@freescale.com>
> > Signed-off-by: Suresh Gupta <suresh.gupta@freescale.com>
> > Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
> > ---
> > Change in v7:
> >               keep v5 version "fall through"
> >
> >  drivers/usb/host/ehci-fsl.c      | 9 +++++++++
> >  drivers/usb/host/fsl-mph-dr-of.c | 3 ++-
> >  2 files changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
> > index 8f3bf3efb038..ef3dfd33a62e 100644
> > --- a/drivers/usb/host/ehci-fsl.c
> > +++ b/drivers/usb/host/ehci-fsl.c
> > @@ -236,6 +236,15 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
> >               portsc |= PORT_PTS_PTW;
> >               /* fall through */
> >       case FSL_USB2_PHY_UTMI:
> > +             /* Presence of this node "has_fsl_erratum_a006918"
> > +              * in device-tree is used to stop USB controller
> > +              * initialization in Linux
> > +              */
> > +             if (pdata->has_fsl_erratum_a006918) {
> > +                     dev_warn(dev, "USB PHY clock invalid\n");
> > +                     return -EINVAL;
> > +             }
> > +
> 
> You need a /* fall through */ comment here, right?
> 
HI greg k-h.

Thanks your feedback!

Yes ,it is needed, because this case doesn't have break, in addition I will add a "/* fall through*/" in
case FSL_USB2_PHY_UTMI, please you note.
Thanks

Best Regards,
Yinbo Zhu.

> thanks,
> 
> greg k-h