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References: <20210518111640.243559-1-kai.heng.feng@canonical.com> <f5d2e440-e777-7ef1-db4b-0f50a8a5f6e1@linux.intel.com>
In-Reply-To: <f5d2e440-e777-7ef1-db4b-0f50a8a5f6e1@linux.intel.com>
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
Date:   Tue, 18 May 2021 20:35:45 +0800
Message-ID: <CAAd53p6MS=nZ=rK3kEe4TpBO99cvBkbntcTJpNs2cxw1CjThtg@mail.gmail.com>
Subject: Re: [PATCH] xhci: State explicitly when the controller is inaccessible
To:     Mathias Nyman <mathias.nyman@linux.intel.com>
Cc:     Mathias Nyman <mathias.nyman@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "open list:USB XHCI DRIVER" <linux-usb@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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On Tue, May 18, 2021 at 8:19 PM Mathias Nyman
<mathias.nyman@linux.intel.com> wrote:
>
> On 18.5.2021 14.16, Kai-Heng Feng wrote:
> > Sometimes the dmesg says "Controller not ready at resume" because CNR is
> > flagged. But what actually happens is that the whole USBSTS becomes
> > inaccessible, and the reason could be disabled PCI I/O space or faulty
> > firmware/hardware.
> >
> > So state the reason explicitly to make the message more clear.
> >
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > ---
> >  drivers/usb/host/xhci.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> > index ca9385d22f68..0e6fbe1f4fcc 100644
> > --- a/drivers/usb/host/xhci.c
> > +++ b/drivers/usb/host/xhci.c
> > @@ -1117,8 +1117,9 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
> >               retval = xhci_handshake(&xhci->op_regs->status,
> >                                       STS_CNR, 0, 10 * 1000 * 1000);
> >               if (retval) {
> > -                     xhci_warn(xhci, "Controller not ready at resume %d\n",
> > -                               retval);
> > +                     xhci_warn(xhci, "Controller is %s at resume %d\n",
> > +                               retval == -ENODEV ? "inaccessible" :
> > +                               "not ready", retval);
>
> Old way did print out retval, and was greppable.
> Not sure this is an improvement

That's true. Maybe it's just me, but I can't directly mapped the value
to -ENODEV at first glance.
But in essence this is just a cosmetic change.

Kai-Heng

>
> -Mathias