Re: [PATCH RFT 4/7] phy: qcom: qmp-combo: register a typec mux to change the QPHY_MODE

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On Thu, 29 Feb 2024 at 17:47, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>
> On 29/02/2024 16:25, Dmitry Baryshkov wrote:
> > On Thu, 29 Feb 2024 at 15:08, Neil Armstrong <neil.armstrong@linaro.org> wrote:
> >>
> >> Register a typec mux in order to change the PHY mode on the Type-C
> >> mux events depending on the mode and the svid when in Altmode setup.
> >>
> >> The DisplayPort phy should be left enabled if is still powered on
> >> by the DRM DisplayPort controller, so bail out until the DisplayPort
> >> PHY is not powered off.
> >>
> >> The Type-C Mode/SVID only changes on plug/unplug, and USB SAFE states
> >> will be set in between of USB-Only, Combo and DisplayPort Only so
> >> this will leave enough time to the DRM DisplayPort controller to
> >> turn of the DisplayPort PHY.
> >
> > I think this is not fully correct. Please correct me if I'm wrong, but
> > it is possible to switch between USB / USB+DP / DP-only at runtime.
> > See the Status Update and Configure commands.
>
> Yes, but the current implementation is still valid because we need to
> have the DP powered-off before changing the PHY mode.

Even for switching between 2 lane and 4 lane modes?

I'll check how my USB-A+DP dongles work with respect to the altmode
configuration.

>
> I never encountered such setup and I have no idea how to test this.
>
> >
> >>
> >> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>


-- 
With best wishes
Dmitry