On Tue, Oct 24, 2023 at 02:08:33AM +0300, Dmitry Baryshkov wrote:
> On Tue, 24 Oct 2023 at 01:47, Bjorn Andersson <quic_bjorande@xxxxxxxxxxx> wrote:
> >
> > On Tue, Oct 24, 2023 at 12:47:26AM +0300, Dmitry Baryshkov wrote:
> > > On sevral Qualcomm platforms (SC8180X, SM8350, SC8280XP) a call to
> > > UCSI_GET_PDOS for non-PD partners will cause a firmware crash with no
> > > easy way to recover from it. Since we have no easy way to determine
> > > whether the partner really has PD support, shortcut UCSI_GET_PDOS on
> > > such platforms. This allows us to enable UCSI support on such devices.
> > >
> >
> > Really nice to see this. Thanks.
> >
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> > > ---
> > > drivers/usb/typec/ucsi/ucsi.c | 3 +++
> > > drivers/usb/typec/ucsi/ucsi.h | 3 +++
> > > drivers/usb/typec/ucsi/ucsi_glink.c | 3 +++
> > > 3 files changed, 9 insertions(+)
> > >
> > > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> > > index 61b64558f96c..5392ec698959 100644
> > > --- a/drivers/usb/typec/ucsi/ucsi.c
> > > +++ b/drivers/usb/typec/ucsi/ucsi.c
> > > @@ -578,6 +578,9 @@ static int ucsi_read_pdos(struct ucsi_connector *con,
> > > u64 command;
> > > int ret;
> > >
> > > + if (ucsi->quirks & UCSI_NO_PARTNER_PDOS)
> > > + return 0;
> > > +
> > > command = UCSI_COMMAND(UCSI_GET_PDOS) | UCSI_CONNECTOR_NUMBER(con->num);
> > > command |= UCSI_GET_PDOS_PARTNER_PDO(is_partner);
> > > command |= UCSI_GET_PDOS_PDO_OFFSET(offset);
> > > diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> > > index 474315a72c77..6478016d5cb8 100644
> > > --- a/drivers/usb/typec/ucsi/ucsi.h
> > > +++ b/drivers/usb/typec/ucsi/ucsi.h
> > > @@ -317,6 +317,9 @@ struct ucsi {
> > > #define EVENT_PENDING 0
> > > #define COMMAND_PENDING 1
> > > #define ACK_PENDING 2
> > > +
> > > + unsigned long quirks;
> > > +#define UCSI_NO_PARTNER_PDOS BIT(0) /* Don't read partner's PDOs */
> > > };
> > >
> > > #define UCSI_MAX_SVID 5
> > > diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c
> > > index db6e248f8208..5c159e7b2b65 100644
> > > --- a/drivers/usb/typec/ucsi/ucsi_glink.c
> > > +++ b/drivers/usb/typec/ucsi/ucsi_glink.c
> > > @@ -327,6 +327,8 @@ static int pmic_glink_ucsi_probe(struct auxiliary_device *adev,
> > > if (ret)
> > > return ret;
> > >
> > > + ucsi->ucsi->quirks = id->driver_data;
> > > +
> > > ucsi_set_drvdata(ucsi->ucsi, ucsi);
> > >
> > > device_for_each_child_node(dev, fwnode) {
> > > @@ -379,6 +381,7 @@ static void pmic_glink_ucsi_remove(struct auxiliary_device *adev)
> > >
> > > static const struct auxiliary_device_id pmic_glink_ucsi_id_table[] = {
> > > { .name = "pmic_glink.ucsi", },
> > > + { .name = "pmic_glink.ucsi-no-pdos", .driver_data = UCSI_NO_PARTNER_PDOS, },
> >
> > In altmode and battmgr drivers we apply quirks based on the compatible
> > of the pmic_glink of_node.
>
> ... and I can't say that I like that. In typical drivers we perform
> driver tuning by looking at the device's data (e.g. by using
> of_device_is_compatible or by of_device_get_match_data. Checking the
> parent device seems like breaking the layering.
It felt like it was the cleaner option of the two when I did it. I think
there was some variation of quirks which made me feel this would grow
large - but I might misremember things now.
> But if you insist, I can follow that approach.
I insist that we should use the same mechanism of dealing with the
quirks across the three parts, and following the existing approach
doesn't seem too unreasonable...
Thanks,
Bjorn
