Re: [linux-sunxi] [PATCH v2 3/7] phy: usb: sunxi: Introduce Allwinner A31 USB PHY support

From: Maxime Ripard
Date: Mon May 12 2014 - 11:05:14 EST


On Mon, May 12, 2014 at 05:14:26PM +0800, Chen-Yu Tsai wrote:
> Hi,
>
> On Sat, May 10, 2014 at 8:56 PM, Maxime Ripard
> <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
> > The USB phy controller in the A31 differs mostly from the older controllers
> > because it has a clock dedicated for each phy, while the older ones were having
> > a single clock for all the phys.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > ---
> > drivers/phy/phy-sun4i-usb.c | 35 ++++++++++++++++++++++++++---------
> > 1 file changed, 26 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c
> > index e6e6c4ba7145..8bd89430d945 100644
> > --- a/drivers/phy/phy-sun4i-usb.c
> > +++ b/drivers/phy/phy-sun4i-usb.c
> > @@ -61,7 +61,6 @@
> > #define MAX_PHYS 3
> >
> > struct sun4i_usb_phy_data {
> > - struct clk *clk;
> > void __iomem *base;
> > struct mutex mutex;
> > int num_phys;
> > @@ -71,6 +70,7 @@ struct sun4i_usb_phy_data {
> > void __iomem *pmu;
> > struct regulator *vbus;
> > struct reset_control *reset;
> > + struct clk *clk;
> > int index;
> > } phys[MAX_PHYS];
> > };
> > @@ -146,13 +146,13 @@ static int sun4i_usb_phy_init(struct phy *_phy)
> > struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
> > int ret;
> >
> > - ret = clk_prepare_enable(data->clk);
> > + ret = clk_prepare_enable(phy->clk);
> > if (ret)
> > return ret;
> >
> > ret = reset_control_deassert(phy->reset);
> > if (ret) {
> > - clk_disable_unprepare(data->clk);
> > + clk_disable_unprepare(phy->clk);
> > return ret;
> > }
> >
> > @@ -170,11 +170,10 @@ static int sun4i_usb_phy_init(struct phy *_phy)
> > static int sun4i_usb_phy_exit(struct phy *_phy)
> > {
> > struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
> > - struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
> >
> > sun4i_usb_phy_passby(phy, 0);
> > reset_control_assert(phy->reset);
> > - clk_disable_unprepare(data->clk);
> > + clk_disable_unprepare(phy->clk);
> >
> > return 0;
> > }
> > @@ -228,8 +227,10 @@ static int sun4i_usb_phy_probe(struct platform_device *pdev)
> > struct phy_provider *phy_provider;
> > struct reset_control *reset;
> > struct regulator *vbus;
> > + bool dedicated_clocks;
>
> No default?
>
> > struct resource *res;
> > struct phy *phy;
> > + struct clk *clk;
> > char name[16];
> > int i;
> >
> > @@ -249,15 +250,20 @@ static int sun4i_usb_phy_probe(struct platform_device *pdev)
> > else
> > data->disc_thresh = 2;
> >
> > + if (of_device_is_compatible(np, "allwinner,sun6i-a31-usb-phy"))
> > + dedicated_clocks = true;
> > +
>
> dedicated_clocks is more than likely to be true from leftover data
> on the stack. This results in the usb phy driver probe failing, and
> the usb host drivers left in perpetual probe deferral on my Cubietruck.
>
> Adding an else section fixes this.

Oh, yes. Stupid me. It used to be in a kzalloc'd section, so I didn't
have the error, and didn't properly test it because it was trivial.

Thanks for catching this, I'll submit a v3.

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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