On 29/02/2024 16:54, Dmitry Baryshkov wrote:

On Thu, 29 Feb 2024 at 17:47, Neil Armstrong [off-list ref] wrote:

quoted

On 29/02/2024 16:25, Dmitry Baryshkov wrote:

quoted

On Thu, 29 Feb 2024 at 15:08, Neil Armstrong [off-list ref] wrote:

quoted

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.

quoted

I never encountered such setup and I have no idea how to test this.

quoted

quoted

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

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