Re: [PATCH v5 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy

From: "Heiko Stübner" <heiko@sntech.de>
To: Guenter Roeck <groeck@google.com>
Cc: Frank Wang <frank.wang@rock-chips.com>,
	Douglas Anderson <dianders@chromium.org>,
	Guenter Roeck <linux@roeck-us.net>,
	Guenter Roeck <groeck@chromium.org>,
	jwerner@chromium.org, kishon@ti.com, robh+dt@kernel.org,
	pawel.moll@arm.com, mark.rutland@arm.com,
	ijc+devicetree@hellion.org.uk, Kumar Gala <galak@codeaurora.org>,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-rockchip@lists.infradead.org,
	Ziyuan Xu <xzy.xu@rock-chips.com>,
	Kever Yang <kever.yang@rock-chips.com>,
	Tao Huang <huangtao@rock-chips.com>,
	william.wu@rock-chips.com
Subject: Re: [PATCH v5 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy
Date: Tue, 14 Jun 2016 16:00:24 +0200	[thread overview]
Message-ID: <4065185.1IWsBDlcMJ@diego> (raw)
In-Reply-To: <CABXOdTfzDeg3KOmEkJkeUWs76wFind89D-bSrs=7-jSxmdhSHQ@mail.gmail.com>

Am Dienstag, 14. Juni 2016, 06:50:31 schrieb Guenter Roeck:
> On Tue, Jun 14, 2016 at 6:27 AM, Heiko Stübner <heiko@sntech.de> wrote:
> > Am Montag, 13. Juni 2016, 10:10:10 schrieb Frank Wang:
> >> The newer SoCs (rk3366, rk3399) take a different usb-phy IP block
> >> than rk3288 and before, and most of phy-related registers are also
> >> different from the past, so a new phy driver is required necessarily.
> >> 
> >> Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
> >> ---

[...]

> >> +static int rockchip_usb2phy_init(struct phy *phy)
> >> +{
> >> +     struct rockchip_usb2phy_port *rport = phy_get_drvdata(phy);
> >> +     struct rockchip_usb2phy *rphy = dev_get_drvdata(phy->dev.parent);
> >> +     int ret;
> >> +
> >> 
> >         if (!rport->port_cfg)
> >         
> >                 return 0;
> > 
> > Otherwise the currently empty otg-port will cause null-pointer
> > dereferences
> > when it gets assigned in the devicetree already.
> 
> Not really, at least not here - that port should not have port_id set
> to USB2PHY_PORT_HOST.
> 
> Does it even make sense to instantiate the otg port ? Is it going to
> do anything without port configuration ?

Ok, that would be the other option - not creating the phy in the driver.

Or from what I've seen, handling it as similar to the host-port should work 
initially as well most likely, supplying the additional otg-parts later on.

[...]

> >> +static int rockchip_usb2phy_exit(struct phy *phy)
> >> +{
> >> +     struct rockchip_usb2phy_port *rport = phy_get_drvdata(phy);
> >> +
> >> 
> >         if (!rport->port_cfg)
> >         
> >                 return 0;
> 
> No access to port_cfg here ?

sorry, one copy'n'paste to many :-)