Re: [PATCH 3/7] phy: qcom-qmp-combo: Introduce orientation variable

From: Johan Hovold
Date: Thu May 04 2023 - 09:44:52 EST


On Wed, May 03, 2023 at 08:29:07PM -0700, Bjorn Andersson wrote:
> On Tue, May 02, 2023 at 01:48:16PM +0200, Johan Hovold wrote:
> > On Mon, Apr 24, 2023 at 08:40:06PM -0700, Bjorn Andersson wrote:

> > > static void qmp_v3_dp_aux_init(struct qmp_combo *qmp);
> > > @@ -1955,29 +1962,23 @@ static void qmp_v3_configure_dp_tx(struct qmp_combo *qmp)
> > > static bool qmp_combo_configure_dp_mode(struct qmp_combo *qmp)
> > > {
> > > u32 val;
> > > - bool reverse = false;
> > > + bool reverse = qmp->orientation == TYPEC_ORIENTATION_REVERSE;

> > It also looks like these callbacks end up being called without holding
> > the qmp->phy_mutex via phy->power_on(). Perhaps there is no risk for a
> > concurrent switch notification and dp phy power-on but it's not that
> > obvious.

> It seems we're arriving here from hpd_event_thread(), while
> phy_power_on() and phy_power_off() will be called in some other context.
> I've not been able to convince myself if DP driver ensures ordering, or
> if we have an existing race here...

> Unless you insist, I would prefer to follow up with an additional patch
> once we've landed this series. The fix will depend on the phy_mutex
> shuffling patch anyways...

Sure.

But perhaps you can just move the orientation == qmp->orientation check
under the mutex in qmp_combo_typec_switch_set() for now (in case I
forgot to point that out earlier).

Johan