Re: [PATCH v2 1/2] usb: ulpi: defer ulpi_register on ulpi_read_id timeout

[Stephen Boyd <sboyd@kernel.org>]

Quoting Ferry Toth (2022-11-11 06:04:16)
> + Stephen Boyd
> 
> On 10-11-2022 22:11, Ferry Toth wrote:
> > Since commit 0f010171
> > Dual Role support on Intel Merrifield platform broke due to rearranging
> > the call to dwc3_get_extcon().
> > 
> > It appears to be caused by ulpi_read_id() on the first test write failing
> > with -ETIMEDOUT. Currently ulpi_read_id() expects to discover the phy via
> > DT when the test write fails and returns 0 in that case even if DT does not
> > provide the phy. As a result usb probe completes without phy.
> > 
> > Signed-off-by: Ferry Toth <ftoth@exalondelft.nl>
> > ---
> >   drivers/usb/common/ulpi.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
> > index d7c8461976ce..60e8174686a1 100644
> > --- a/drivers/usb/common/ulpi.c
> > +++ b/drivers/usb/common/ulpi.c
> > @@ -207,7 +207,7 @@ static int ulpi_read_id(struct ulpi *ulpi)
> >       /* Test the interface */
> >       ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
> >       if (ret < 0)
> > -             goto err;
> > +             return ret;
> >   
> >       ret = ulpi_read(ulpi, ULPI_SCRATCH);
> >       if (ret < 0)
> 
> Would this affect others phys (like qcom HSIC)? I'm not sure if failing 
> the test write is a normal behavior.

I don't think failing a test write is normal behavior. I don't have this
hardware on hand anymore though, so I can't help test it. Looks OK to me
though:

Reviewed-by: Stephen Boyd <sboyd@kernel.org>