fail to light up display through dp port

[TedL]

Sir, 

  We are using i.mx8mq in our project. The system uses MIPI as the main display, the DP port signal was connected to TUSB546 and  TPS65994AD to configure the mux to achieve the DP alt mode. We failed to light up the display through the DP alt mode with some type-C to HDMI dongle ( or hub with HDMI output port). When the issue happened, we will see error log from console output like below and also reports invalid edid. 

[ 2.428568][ T1] [drm] Initialized imx-dcss 1.0.0 20190917 for 32e00000.display-controller on minor 0
[ 2.434186][ T8] hub 2-0:1.0: USB hub found
[ 2.451544][ T1] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2
[ 2.457423][ T8] hub 2-0:1.0: 1 port detected
[ 2.468960][ T1] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2
[ 2.504887][ T1] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2
[ 2.527717][ T1] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2
[ 2.543435][ T1] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_get_edid_block [cdns_mhdp_drmcore]] *ERROR* get block[0] edid failed: -22
[ 2.555852][ T1] [drm:cdns_dp_connector_get_modes [cdns_mhdp_drmcore]] *ERROR* Invalid edid
[ 2.565811][ T1] imx-dcss 32e00000.display-controller: [drm] fb0: imx-dcssdrmfb frame buffer device
[ 2.582262][ T42] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2
[ 2.605112][ T42] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2
[ 2.628436][ T42] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2
[ 2.631334][ T8] nwl-dsi 30a00000.mipi-dsi: [drm:nwl_dsi_probe [nwl_dsi]] Using LCDIF as input source
[ 2.652052][ T42] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2
[ 2.653712][ T90] usb 1-1: new high-speed USB device number 2 using xhci-hcd
[ 2.655654][ T8] [drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc@0/bus@30800000/mipi-dsi@30a00000 to encoder None-34: -517[ 2.656162][ T1] tps65994 0-0020: current version: Ver.0.47
[ 2.669366][ T42] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_get_edid_block [cdns_mhdp_drmcore]] *ERROR* get block[0] edid failed: -22
[ 2.716303][ T42] [drm:cdns_dp_connector_get_modes [cdns_mhdp_drmcore]] *ERROR* Invalid edid
[ 2.738275][ T8] [drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc@0/bus@30800000/mipi-dsi@30a00000 to encoder None-34: -517
[ 2.790179][ T42] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:3:6 vs 1:3:5
[ 2.793264][ T8] [drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc@0/bus@30800000/mipi-dsi@30a00000 to encoder None-34: -517
[ 2.810516][ T42] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:3:6 vs 1:3:5
[ 2.834094][ T1] __power_supply_register: Expected proper parent device for 'battery'
[ 2.837333][ T90] usb 1-1: New USB device found, idVendor=0424, idProduct=2514, bcdDevice= b.b3
[ 2.842554][ T1] __power_supply_register: Expected proper parent device for 'usb'
[ 2.851125][ T90] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0

How to fix the error "cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_mailbox_validate_receive [cdns_mhdp_drmcore]] Hmmm spurious mailbox data maybe, cleaning out...1:2:130 vs 1:2:2" ?

Thanks, 

Ted

[TedL]

Hi Joanxie, 

  Thanks for reply, I share the information with you in private message, please check . 

Thanks, 

Ted

[joanxie]

do you mind sharing the HW connection and dts file?