Messages in this thread | | | Date | Thu, 29 Feb 2024 16:57:43 +0100 | From | neil.armstrong@linaro ... | Subject | Re: [PATCH RFT 4/7] phy: qcom: qmp-combo: register a typec mux to change the QPHY_MODE |
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On 29/02/2024 16:54, Dmitry Baryshkov wrote: > 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?
So the Altmode pin assignment says how much lanes you can get (2 or 4), and AUX data will say how much the adapter/display supports.
My native DP monitor uses the 4 lanes, while my USB-C->HDMI dongles declares the 4lanes pin assigment but DP controller only ever tries 2 lanes.
I don't have USB-C->HDMI with 4lanes DP, but it should work fine.
Neil
> > 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> > >
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