# AGX Xavier HDMI working abnormally: dc\_poll\_register 0x41: timeout **URL:** \ **Category:** Jetson AGX Xavier\ **Tags:** hdmi\ **Created:** [October 30, 2024, 11:20am UTC](https://forums.developer.nvidia.com/t/agx-xavier-hdmi-working-abnormally-dc-poll-register-0x41-timeout/311697 "2024-10-30T11:20:32Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![newbie.lei](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@newbie.lei](https://forums.developer.nvidia.com/u/newbie.lei)\ **Post date:** [October 30, 2024, 11:20am UTC](https://forums.developer.nvidia.com/t/agx-xavier-hdmi-working-abnormally-dc-poll-register-0x41-timeout/311697/1 "2024-10-30T11:20:33Z")
Hi, We use Jetson AGX Xavier, L4T version is R3560. At one point when we turned on the AGX, we noticed that the HDMI monitor stayed black and did not display a screen. We used the xrandr command to do a --auto and --off on this HDMI, and the corresponding dmesg prints as follows: ```shell xrandr --output HDMI-2 --auto ``` ![img_v3_02g5_1e1453e2-e254-4adf-a9ac-73f6c0c3596g](https://global.discourse-cdn.com/nvidia/original/4X/2/3/3/2336972579741dcefaa2f4adb6b2eb295b02b063.jpeg) ```shell xrandr --output HDMI-2 --off ``` ![img_v3_02g5_ff9df730-d855-46b9-9438-5e30dad338eg](https://global.discourse-cdn.com/nvidia/original/4X/8/d/a/8da87b1427b94ba571d362ee8fe93854d73fc69e.jpeg) We plugged and unplugged the HDMI monitor and dmesg came up with the following print: ```auto [1483.992161] usb 1-3: USB disconnect, device number 10 [1484.162648] extcon-disp-state external-connection:disp-state: cable 51 state 0 [1484.162676] Extcon HDMI: HPD disabled [1484.162681] tegradc 15220000.display: hdmi: unplugged [1484.164703] tegradc 15200000.display: blank - powerdown [1484.164729] tegradc 15200000.display: unblank [1484.218489] tegradc 15200000.display: dc_poll_register 0x41: timeout [1484.218496] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1484.270495] tegradc 15200000.display: dc_poll_register 0x41: timeout [1484.270501] tegradc 15200000.display: timeout waiting for win assignments to promote [1484.270504] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1484.271420] tegradc 15200000.display: unblank [1484.326481] tegradc 15200000.display: dc_poll_register 0x41: timeout [1484.326487] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1484.378485] tegradc 15200000.display: dc_poll_register 0x41: timeout [1484.378491] tegradc 15200000.display: timeout waiting for win assignments to promote [1484.378495] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1484.379347] tegradc 15210000.display: blank - powerdown [1484.379359] tegradc 15220000.display: blank - powerdown [1504.801568] usb 1-3: new full-speed USB device number 11 using tegra-xusb [1504.875829] tegradc 15220000.display: hdmi: edid read failed [1504.876063] tegradc 15220000.display: hdmi: using fallback edid [1504.877582] extcon-disp-state external-connection:disp-state: cable 51 state 1 [1504.877589] Extcon HDMI: HPD enabled [1504.877595] tegradc 15220000.display: hdmi: plugged [1504.877828] tegradc 15200000.display: blank - powerdown [1504.877851] tegradc 15200000.display: unblank [1504.881441] tegradc 15220000.display: hdmi: tegra_edid_read_block(0) returned err -121 [1504.881447] tegradc 15220000.display: hdmi_recheck_edid: read_edid_into_buffer() returned -121 [1504.881450] tegradc 15220000.display: hdmi: unable to read EDID [1504.933518] tegradc 15200000.display: dc_poll_register 0x41: timeout [1504.933524] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1504.950799] usb 1-3: New USB device found, idVendor=0eef, idProduct=c002, bcdDevice=21.00 [1504.950804] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [1504.950827] usb 1-3: Product: eGalaxTouch P80H46 7021 v00_T2 k4.18.204 [1504.950839] usb 1-3: Manufacturer: eGalax Inc. [1504.956755] input: eGalax Inc. eGalaxTouch P80H46 7021 v00_T2 k4.18.204 as /devices/platform/3610000.xhci/usb1/1-3/1-3:1.0/0003:0EEF:C002.0005/input/input14 [1504.957088] input: eGalax Inc. eGalaxTouch P80H46 7021 v00_T2 k4.18.204 Mouse as /devices/platform/3610000.xhci/usb1/1-3/1-3:1.0/0003:0EEF:C002.0005/input/input16 [1504.957533] hid-multitouch 0003:0EEF:C002.0005: input,hiddev96,hidraw0: USB HID v1.11 Mouse [eGalax Inc. eGalaxTouch P80H46 7021 v00_T2 k4.18.204] on usb-3610000.xhci-3/input0 [1504.985514] tegradc 15200000.display: dc_poll_register 0x41: timeout [1504.985521] tegradc 15200000.display: timeout waiting for win assignments to promote [1504.985525] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1504.986438] tegradc 15200000.display: unblank [1505.041519] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.041525] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1505.093507] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.093513] tegradc 15200000.display: timeout waiting for win assignments to promote [1505.093517] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1505.094393] tegradc 15210000.display: blank - powerdown [1505.094418] tegradc 15220000.display: blank - powerdown [1505.201563] extcon-disp-state external-connection:disp-state: cable 51 state 0 [1505.201572] Extcon HDMI: HPD disabled [1505.201597] tegradc 15220000.display: hdmi: unplugged [1505.344847] tegradc 15200000.display: blank - powerdown [1505.344873] tegradc 15200000.display: unblank [1505.401484] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.401492] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1505.453496] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.453502] tegradc 15200000.display: timeout waiting for win assignments to promote [1505.453506] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1505.454368] tegradc 15200000.display: unblank [1505.509482] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.509488] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1505.561475] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.561481] tegradc 15200000.display: timeout waiting for win assignments to promote [1505.561485] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1505.562266] tegradc 15210000.display: blank - powerdown [1505.562279] tegradc 15220000.display: blank - powerdown [1505.732586] extcon-disp-state external-connection:disp-state: cable 51 state 1 [1505.732592] Extcon HDMI: HPD enabled [1505.732613] tegradc 15220000.display: hdmi: plugged [1505.736905] tegradc 15200000.display: blank - powerdown [1505.736946] tegradc 15200000.display: unblank [1505.793480] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.793487] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1505.845478] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.845486] tegradc 15200000.display: timeout waiting for win assignments to promote [1505.845490] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1505.846327] tegradc 15200000.display: unblank [1505.901464] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.901470] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1505.953468] tegradc 15200000.display: dc_poll_register 0x41: timeout [1505.953474] tegradc 15200000.display: timeout waiting for win assignments to promote [1505.953479] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1505.954335] tegradc 15210000.display: blank - powerdown [1505.954347] tegradc 15220000.display: blank - powerdown [1509.189385] extcon-disp-state external-connection:disp-state: cable 51 state 0 [1509.189412] Extcon HDMI: HPD disabled [1509.189418] tegradc 15220000.display: hdmi: unplugged [1509.190534] tegradc 15200000.display: blank - powerdown [1509.190564] tegradc 15200000.display: unblank [1509.245298] tegradc 15200000.display: dc_poll_register 0x41: timeout [1509.245304] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1509.297294] tegradc 15200000.display: dc_poll_register 0x41: timeout [1509.297317] tegradc 15200000.display: timeout waiting for win assignments to promote [1509.297322] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1509.298162] tegradc 15200000.display: unblank [1509.353304] tegradc 15200000.display: dc_poll_register 0x41: timeout [1509.353310] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1509.405287] tegradc 15200000.display: dc_poll_register 0x41: timeout [1509.405292] tegradc 15200000.display: timeout waiting for win assignments to promote [1509.405297] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1509.406077] tegradc 15210000.display: blank - powerdown [1509.406089] tegradc 15220000.display: blank - powerdown [1509.720590] extcon-disp-state external-connection:disp-state: cable 51 state 1 [1509.720596] Extcon HDMI: HPD enabled [1509.720618] tegradc 15220000.display: hdmi: plugged [1509.722756] tegradc 15200000.display: blank - powerdown [1509.722780] tegradc 15200000.display: unblank [1509.777290] tegradc 15200000.display: dc_poll_register 0x41: timeout [1509.777296] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1509.829277] tegradc 15200000.display: dc_poll_register 0x41: timeout [1509.829282] tegradc 15200000.display: timeout waiting for win assignments to promote [1509.829286] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1509.830137] tegradc 15200000.display: unblank [1509.885277] tegradc 15200000.display: dc_poll_register 0x41: timeout [1509.885282] tegradc 15200000.display: timeout waiting for postcomp init state to promote [1509.937284] tegradc 15200000.display: dc_poll_register 0x41: timeout [1509.937292] tegradc 15200000.display: timeout waiting for win assignments to promote [1509.937296] tegradc 15200000.display: tegra_nvdisp_head_enable, failed head enable [1509.938178] tegradc 15210000.display: blank - powerdown [1509.938189] tegradc 15220000.display: blank - powerdown [1513.829163] extcon-disp-state external-connection:disp-state: cable 51 state 0 ``` Most suspicious is the following print: **[1509.298162] tegradc 15200000.display: unblank** **[1509.353304] tegradc 15200000.display: dc\_poll\_register 0x41: timeout** **[1509.353310] tegradc 15200000.display: timeout waiting for postcomp init state to promote** **[1509.405287] tegradc 15200000.display: dc\_poll\_register 0x41: timeout** **[1509.405292] tegradc 15200000.display: timeout waiting for win assignments to promote** **[1509.405297] tegradc 15200000.display: tegra\_nvdisp\_head\_enable, failed head enable** What does the above abnormal printing mean? What are the possible causes of this abnormality? How should we solve this problem? ---
**Author:** ![newbie.lei](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@newbie.lei](https://forums.developer.nvidia.com/u/newbie.lei)\ **Post date:** [October 30, 2024, 11:22am UTC](https://forums.developer.nvidia.com/t/agx-xavier-hdmi-working-abnormally-dc-poll-register-0x41-timeout/311697/2 "2024-10-30T11:22:35Z")
By the way, after we reset the AGX, it was back to normal and the monitor could display the screen normally. This is an occasional problem. ---
**Author:** ![WayneWWW](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/waynewww/32/14043_2.png) [@WayneWWW](https://forums.developer.nvidia.com/u/WayneWWW)\ **Post date:** [October 30, 2024, 2:18pm UTC](https://forums.developer.nvidia.com/t/agx-xavier-hdmi-working-abnormally-dc-poll-register-0x41-timeout/311697/3 "2024-10-30T14:18:54Z")
Try this patch to the device tree. [https://docs.nvidia.com/jetson/archives/r35.6.0/DeveloperGuide/SD/Kernel/DisplayConfigurationAndBringUp/XavierDisplayconfig.html?highlight=seamless#bypassing-the-seamless-display-issue](https://docs.nvidia.com/jetson/archives/r35.6.0/DeveloperGuide/SD/Kernel/DisplayConfigurationAndBringUp/XavierDisplayconfig.html?highlight=seamless#bypassing-the-seamless-display-issue) ---
**Author:** ![system](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/system/32/68080_2.png) [@system](https://forums.developer.nvidia.com/u/system)\ **Post date:** [November 13, 2024, 2:19pm UTC](https://forums.developer.nvidia.com/t/agx-xavier-hdmi-working-abnormally-dc-poll-register-0x41-timeout/311697/4 "2024-11-13T14:19:32Z")
Closed on November 13, 2024, 2:19pm UTC This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.