Re: [PATCH] phy: core: Add consumer device link support

[Alexandre Torgue <alexandre.torgue@xxxxxx>]

Hi,

On 2/14/20 7:46 PM, Andy Shevchenko wrote:
> On Mon, Feb 10, 2020 at 1:32 PM Alexandre Torgue
> <alexandre.torgue@xxxxxx> wrote:
> > On 2/10/20 9:08 AM, Kishon Vijay Abraham I wrote:
> > > On 07/02/20 12:27 PM, youling 257 wrote:
> > > > test this diff, dwc3 work for my device, thanks.
> > > >
> > > > 2020-02-07 13:16 GMT+08:00, Kishon Vijay Abraham I <kishon@xxxxxx>:
> > > > > On 06/02/20 7:09 PM, youling257 wrote:
> > > > > > This patch cause "dwc3 dwc3.3.auto: failed to create device link to
> > > > > > dwc3.3.auto.ulpi" problem.
> > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=206435
>
> +1 to the report.
> Please revert for v5.6 or provide a fix ASAP!

Kishon, do you plan to do the fix? If not, I'll send it quickly.

Thanks
Alex

> > > > > I'm suspecting there is some sort of reverse dependency with dwc3 ULPI.
> > > > > Can you try the following diff?
> > > > >
> > > > > diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> > > > > index 2eb28cc2d2dc..397311dcb116 100644
> > > > > --- a/drivers/phy/phy-core.c
> > > > > +++ b/drivers/phy/phy-core.c
> > > > > @@ -687,7 +687,7 @@ struct phy *phy_get(struct device *dev, const char
> > > > > *string)
> > > > >
> > > > >           get_device(&phy->dev);
> > > > >
> > > > > -       link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
> > > > > +       link = device_link_add(dev, &phy->dev, DL_FLAG_SYNC_STATE_ONLY);
> > > > >           if (!link) {
> > > > >                   dev_err(dev, "failed to create device link to %s\n",
> > > > >                           dev_name(phy->dev.parent));
> > > > > @@ -802,7 +802,7 @@ struct phy *devm_of_phy_get(struct device *dev,
> > > > > struct device_node *np,
> > > > >                   return phy;
> > > > >           }
> > > > >
> > > > > -       link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
> > > > > +       link = device_link_add(dev, &phy->dev, DL_FLAG_SYNC_STATE_ONLY);
> > > > >           if (!link) {
> > > > >                   dev_err(dev, "failed to create device link to %s\n",
> > > > >                           dev_name(phy->dev.parent));
> > > > > @@ -851,7 +851,7 @@ struct phy *devm_of_phy_get_by_index(struct device
> > > > > *dev, struct device_node *np,
> > > > >           *ptr = phy;
> > > > >           devres_add(dev, ptr);
> > > > >
> > > > > -       link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
> > > > > +       link = device_link_add(dev, &phy->dev, DL_FLAG_SYNC_STATE_ONLY);
> > > > >           if (!link) {
> > > > >                   dev_err(dev, "failed to create device link to %s\n",
> > > > >                           dev_name(phy->dev.parent));Parent
> > >
> > > Can you check if this doesn't affect the suspend/resume ordering?
> >
> > With this fix, suspend/resume ordering is broken on my side. What do you
> > think to keep the STATELESS flag and to only display a warn if
> > "device_link_add" returns an error ? It's not "smart" but it could
> > solved our issue.
> >
> > As a lot of improvements have been recently done on device link topic by
> > Saravana, we could check with him what is the way to follow.
> >
> > Regards
> > Alex
> >
> > > Thanks
> > > Kishon