RE: [EXT] Re: [PATCH v5 4/5] usb: host: Stops USB controller init if PLL fails to lock

[Yinbo Zhu]

> -----Original Message-----
> From: Alan Stern [mailto:stern@xxxxxxxxxxxxxxxxxxx]
> Sent: 2019年5月9日 0:50
> To: Yinbo Zhu <yinbo.zhu@xxxxxxx>
> Cc: Xiaobo Xie <xiaobo.xie@xxxxxxx>; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; Ramneek Mehresh
> <ramneek.mehresh@xxxxxxxxxxxxx>; Nikhil Badola
> <nikhil.badola@xxxxxxxxxxxxx>; Ran Wang <ran.wang_1@xxxxxxx>;
> linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Jiafei Pan
> <jiafei.pan@xxxxxxx>; Suresh Gupta <suresh.gupta@xxxxxxxxxxxxx>
> Subject: [EXT] Re: [PATCH v5 4/5] usb: host: Stops USB controller init if PLL fails to
> lock
> 
> Caution: EXT Email
> 
> On Wed, 8 May 2019, Yinbo Zhu wrote:
> 
> > From: Ramneek Mehresh <ramneek.mehresh@xxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxx>
> > Signed-off-by: Suresh Gupta <suresh.gupta@xxxxxxxxxxxxx>
> > Signed-off-by: Yinbo Zhu <yinbo.zhu@xxxxxxx>
> > ---
> > Change in v5:
> >               use dev_warn() instead of pr_warn()
> >
> >  drivers/usb/host/ehci-fsl.c      |    5 +++++
> >  drivers/usb/host/fsl-mph-dr-of.c |    3 ++-
> >  2 files changed, 7 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
> > index 1634ac8..90550a6 100644
> > --- a/drivers/usb/host/ehci-fsl.c
> > +++ b/drivers/usb/host/ehci-fsl.c
> > @@ -236,6 +236,11 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
> >               portsc |= PORT_PTS_PTW;
> >               /* fall through */
> >       case FSL_USB2_PHY_UTMI:
> > +             if (pdata->has_fsl_erratum_a006918) {
> > +                     dev_warn(dev, "USB PHY clock invalid\n");
> > +                     return -EINVAL;
> > +             }
> > +
> 
> You need to add a "Fall through" comment between these two cases.
> >       case FSL_USB2_PHY_UTMI_DUAL:
> >               /* PHY_CLK_VALID bit is de-featured from all controller
> >                * versions below 2.4 and is to be checked only for
> 
> Alan Stern
Hi Alan Stern,

Your meaning is to remove "/* fall through*/" or add the erratum commont replace "/* fall through*/"

Regards,
Yinbo