Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
MIME-Version: 1.0
References: <20220412122524.26966-1-surong.pang@gmail.com> <610871b2-1707-dfba-868f-4ddecc4d554d@linux.intel.com>
In-Reply-To: <610871b2-1707-dfba-868f-4ddecc4d554d@linux.intel.com>
From:   surong pang <surong.pang@gmail.com>
Date:   Fri, 22 Apr 2022 10:10:55 +0800
Message-ID: <CAEDbmAT=fZ-kpn13sW4KjB9RuFb_6T4j_eripR54NZ3UciZfqA@mail.gmail.com>
Subject: Re: [PATCH V1 1/1] usb/host: Let usb phy shutdown later
To:     Mathias Nyman <mathias.nyman@linux.intel.com>
Cc:     mathias.nyman@intel.com, Greg KH <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Orson.Zhai@unisoc.com, yunguo.wu@unisoc.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

shared_hcd might be freed already here, but hcd should not be freed
here, because "usb_put_hcd(hcd)" is called later.

Mathias Nyman <mathias.nyman@linux.intel.com> =E4=BA=8E2022=E5=B9=B44=E6=9C=
=8819=E6=97=A5=E5=91=A8=E4=BA=8C 22:43=E5=86=99=E9=81=93=EF=BC=9A
>
> On 12.4.2022 15.25, Surong Pang wrote:
> > From: Surong Pang <surong.pang@unisoc.com>
> >
> > Let usb phy shutdown later in xhci_plat_remove function.
> > Some phy driver doesn't divide 3.0/2.0 very clear.
> > If calls usb_phy_shutdown earlier than usb_remove_hcd(hcd),
> > It will case 10s cmd timeout issue.
> >
> > Call usb phy shutdown later has better compatibility.
> >
> > Signed-off-by: Surong Pang <surong.pang@unisoc.com>
> > ---
> >  drivers/usb/host/xhci-plat.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.=
c
> > index 649ffd861b44..dc73a81cbe9b 100644
> > --- a/drivers/usb/host/xhci-plat.c
> > +++ b/drivers/usb/host/xhci-plat.c
> > @@ -390,7 +390,6 @@ static int xhci_plat_remove(struct platform_device =
*dev)
> >
> >       usb_remove_hcd(shared_hcd);
> >       xhci->shared_hcd =3D NULL;
> > -     usb_phy_shutdown(hcd->usb_phy);
> >
> >       usb_remove_hcd(hcd);
> >       usb_put_hcd(shared_hcd);
> > @@ -398,6 +397,7 @@ static int xhci_plat_remove(struct platform_device =
*dev)
> >       clk_disable_unprepare(clk);
> >       clk_disable_unprepare(reg_clk);
> >       usb_put_hcd(hcd);
> > +     usb_phy_shutdown(hcd->usb_phy);
>
> hcd might be freed already here.
> maybe call usb_phy_shutdown(hcd->usb_phy) before usb_put_hcd(hcd)
>
> -Mathias
>
>