Messages in this thread | | | Date | Tue, 23 Apr 2024 16:08:43 +0200 | From | neil.armstrong@linaro ... | Subject | Re: [PATCH RFT 0/7] arm64: qcom: allow up to 4 lanes for the Type-C DisplayPort Altmode |
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On 23/04/2024 15:03, Konrad Dybcio wrote: > > > On 4/5/24 12:19, Luca Weiss wrote: >> On Fri Apr 5, 2024 at 10:08 AM CEST, Neil Armstrong wrote: >>> Hi Luca, >>> >>> On 29/03/2024 10:02, Luca Weiss wrote: >>>> On Tue Mar 26, 2024 at 10:02 PM CET, Konrad Dybcio wrote: >>>>> On 16.03.2024 5:01 PM, Bjorn Andersson wrote: >>>>>> On Fri, Mar 15, 2024 at 06:35:15PM +0100, Neil Armstrong wrote: >>>>>>> On 15/03/2024 18:19, Luca Weiss wrote: >>>>>>>> On Thu Feb 29, 2024 at 2:07 PM CET, Neil Armstrong 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. >>>>>>>>> >>>>>>>>> The patchset also includes bindings changes and DT changes. >>>>>>>>> >>>>>>>>> This has been successfully tested on an SM8550 board, but the >>>>>>>>> Thinkpad X13s deserved testing between non-PD USB, non-PD DisplayPort, >>>>>>>>> PD USB Hubs and PD Altmode Dongles to make sure the switch works >>>>>>>>> as expected. >>>>>>>>> >>>>>>>>> The DisplayPort 4 lanes setup can be check with: >>>>>>>>> $ cat /sys/kernel/debug/dri/ae01000.display-controller/DP-1/dp_debug >>>>>>>>> name = msm_dp >>>>>>>>> drm_dp_link >>>>>>>>> rate = 540000 >>>>>>>>> num_lanes = 4 >>>>>>>> >>>>>>>> Hi Neil, >>>>>>>> >>>>>>>> I tried this on QCM6490/SC7280 which should also support 4-lane DP but I >>>>>>>> haven't had any success so far. >>>>>>>> >>>>>> [..] >>>>>>>> [ 1775.563969] [drm:dp_ctrl_link_train] *ERROR* max v_level reached >>>>>>>> [ 1775.564031] [drm:dp_ctrl_link_train] *ERROR* link training #1 failed. ret=-11 >>>>>>> >>>>>>> Interesting #1 means the 4 lanes are not physically connected to the other side, >>>>>>> perhaps QCM6490/SC7280 requires a specific way to enable the 4 lanes in the PHY, >>>>>>> or some fixups in the init tables. >>>>>>> >>>>>> >>>>>> I tested the same on rb3gen2 (qcs6490) a couple of weeks ago, with the >>>>>> same outcome. Looking at the AUX reads, after switching to 4-lane the >>>>>> link training is failing on all 4 lanes, in contrast to succeeding only >>>>>> on the first 2 if you e.g. forget to mux the other two. >>>>>> >>>>>> As such, my expectation is that there's something wrong in the QMP PHY >>>>>> (or possibly redriver) for this platform. >>>>> >>>>> Do we have any downstream tag where 4lane dp works? I'm willing to believe >>>>> the PHY story.. >>>> >>>> Just tested on Fairphone 5 downstream and 4 lane appears to work there. >>>> This is with an USB-C to HDMI adapter that only does HDMI. >>>> >>>> FP5:/ # cat /sys/kernel/debug/drm_dp/dp_debug >>>> state=0x20a5 >>>> link_rate=270000 >>>> num_lanes=4 >>>> resolution=2560x1440@60Hz >>>> pclock=241500KHz >>>> bpp=24 >>>> test_req=DP_LINK_STATUS_UPDATED >>>> lane_count=4 >>>> bw_code=10 >>>> v_level=0 >>>> p_level=0 >>>> >>>> Sources are here: >>>> https://gerrit-public.fairphone.software/plugins/gitiles/kernel/msm-5.4/+/refs/heads/odm/rc/target/13/fp5 >>>> And probably more importantly techpack/display: >>>> https://gerrit-public.fairphone.software/plugins/gitiles/platform/vendor/opensource/display-drivers/+/refs/heads/odm/rc/target/13/fp5 >>>> Dts if useful: >>>> https://gerrit-public.fairphone.software/plugins/gitiles/kernel/msm-extra/devicetree/+/refs/heads/kernel/13/fp5 >>> >>> Could you retry with this applied ? >>> >>> https://lore.kernel.org/all/20240405000111.1450598-1-swboyd@chromium.org/ >> >> Unfortunately I do not see any change with this on QCM6490 Fairphone 5 >> and 4-lane DP. > > Hm, could you like dump all the PHY regions up and downstream with the display > connected (and nothing connected) and compare them?
Yes would be great, PHY regions and DP regions as well.
Neil
> > Konrad
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