On Sun, 2018-06-24 at 20:00 +0200, Martin Blumenstingl wrote:
> Hello Chunfeng,
>
> thank you for the patch!
>
> On Fri, Jun 22, 2018 at 8:33 AM Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> wrote:
> >
> > 1. use IS_ERR() but not IS_ERR_OR_NULL() because devm_of_phy_get_by_index()
> > never return NULL value;
> ACK - good catch!
>
> > 2. devm_of_phy_get_by_index() should not fail for a valid index
> I have learned that the PHY framework can return -ENODEV if the PHY is:
> 1. supposed to be handled by the legacy USB PHY framework
> 2. the PHY node is disabled in devicetree
A little confused, we can avoid this error by not using a disabled or
"usb-nop-xceiv" phy in host node.
If ignore error of -ENODEV, we will also skip an error case which we
don't want it happen.
>
> see [0] for the code in the PHY framework and [1] for the discussion
> with Johan (who informed me of case #1, I added him on this mail)
>
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > ---
> > drivers/usb/core/phy.c | 11 ++++-------
> > 1 file changed, 4 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
> > index 9879767..0f972e1 100644
> > --- a/drivers/usb/core/phy.c
> > +++ b/drivers/usb/core/phy.c
> > @@ -23,14 +23,11 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
> > struct list_head *list)
> > {
> > struct usb_phy_roothub *roothub_entry;
> > - struct phy *phy = devm_of_phy_get_by_index(dev, dev->of_node, index);
> > + struct phy *phy;
> >
> > - if (IS_ERR_OR_NULL(phy)) {
> > - if (!phy || PTR_ERR(phy) == -ENODEV)
> > - return 0;
> > - else
> > - return PTR_ERR(phy);
> > - }
> > + phy = devm_of_phy_get_by_index(dev, dev->of_node, index);
> > + if (IS_ERR(phy))
> > + return PTR_ERR(phy);
> @Johan can you please review this as well? maybe we need to keep the
> -ENODEV check
>
>
> Regards
> Martin
>
>
> [0] https://elixir.bootlin.com/linux/v4.18-rc2/source/drivers/phy/phy-core.c#L421
> [1] https://lkml.org/lkml/2018/4/19/88
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