getprop_or_none acts as getprop

[HorizonEmuTeam]

I am getting an error because panel.py couldn't find an optional property. Getprop_or_none() is used, but the program returns getprop()'s error and fails. Expected behaviour is getprop_or_none() ignoring the unfound property and just returning nothing.
Log:
Parsing: dsi-panel-oplus-senna-bc-nt37705-1240-2772-dsc-cmd.dtb
Parsing: oplus_senna_bc_nt37705_1240_2772_dsc_cmd (senna ab575 tm nt37705 dsc cmd mode panel)
WARNING: Multiple display timings are not supported yet, using first!
ERROR: Failed to get property: qcom,mdss-dsi-bl-pmic-control-type
Traceback (most recent call last):
File "/home/user/linux-mdss-dsi-panel-driver-generator/lmdpdg.py", line 77, in
panel = Panel.parse(fdt, offset)
^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/user/linux-mdss-dsi-panel-driver-generator/panel.py", line 334, in parse
return name and Panel(name.as_str(), fdt, node)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/user/linux-mdss-dsi-panel-driver-generator/panel.py", line 233, in init
backlight = fdt.getprop_or_none(node, 'qcom,mdss-dsi-bl-pmic-control-type')
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/user/linux-mdss-dsi-panel-driver-generator/fdt2.py", line 38, in getprop_or_none
prop = self.getprop(nodeoffset, prop_name, [FDT_ERR_NOTFOUND])
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/user/linux-mdss-dsi-panel-driver-generator/fdt2.py", line 32, in getprop
return super().getprop(nodeoffset, prop_name, quiet)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/user/.local/lib/python3.12/site-packages/libfdt.py", line 454, in getprop
return Property(prop_name, bytearray(pdata[0]))
^^^^^^^^^^^^^^^^^^^
TypeError: cannot convert 'NoneType' object to bytearray
dsi-panel-oplus-senna-bc-nt37705-1240-2772-dsc-cmd.dtb does not contain any usable panel specifications

[HorizonEmuTeam]

I am using Python 3.12.3 (main, Nov 6 2024, 18:32:19) and latest current release of linux-mdss-dsi-panel-driver-generator, also pylibfdt from dtc 1.7.2.

[stephan-gh]

This feels related to https://git.kernel.org/pub/scm/utils/dtc/dtc.git/commit/?id=9a969f3b70b07bbf1c9df44a38d7f8d1d3a6e2a5, can you try if latest pylibfdt (from main branch) fixes it?

[MarvelMathesh]

Parsing: dsi-panel-tianma-td4310-1080p-video.dtb
Parsing: td4310_tianma_fhd_video (tianma td4310 fhd video mode dsi panel)
ERROR: Failed to get property: qcom,mdss-dsi-lane-4-state
Traceback (most recent call last):
File "/home/mathesh/Documents/whyred/linux-mdss-dsi-panel-driver-generator/./lmdpdg.py", line 77, in <module>
panel = Panel.parse(fdt, offset)
File "/home/mathesh/Documents/whyred/linux-mdss-dsi-panel-driver-generator/panel.py", line 335, in parse
return name and Panel(name.as_str(), fdt, node)
~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/mathesh/Documents/whyred/linux-mdss-dsi-panel-driver-generator/panel.py", line 242, in __init__
while fdt.getprop_or_none(node, f'qcom,mdss-dsi-lane-{self.lanes}-state') is not None:
~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/mathesh/Documents/whyred/linux-mdss-dsi-panel-driver-generator/fdt2.py", line 38, in getprop_or_none
prop = self.getprop(nodeoffset, prop_name, [FDT_ERR_NOTFOUND])
File "/home/mathesh/Documents/whyred/linux-mdss-dsi-panel-driver-generator/fdt2.py", line 32, in getprop
return super().getprop(nodeoffset, prop_name, quiet)
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/mathesh/.local/lib/python3.13/site-packages/libfdt.py", line 454, in getprop
return Property(prop_name, bytearray(pdata[0]))
~~~~~~~~~^^^^^^^^^^
TypeError: cannot convert 'NoneType' object to bytearray
dsi-panel-tianma-td4310-1080p-video.dtb does not contain any usable panel specifications

/dts-v1/;

/ {
    mdp {
        compatible = "qcom,mdss_mdp";

        /* Add your panels here */
        dsi_td4310_tianma_fhd_video: qcom,mdss_dsi_td4310_tianma_fhd_video {
            qcom,mdss-dsi-panel-name = "tianma td4310 fhd video mode dsi panel";
			/* qcom,mdss-dsi-panel-controller = <&mdss_dsi0>; */
            qcom,mdss-dsi-panel-type = "dsi_video_mode";
            qcom,mdss-dsi-panel-framerate = <60>;
            qcom,mdss-dsi-virtual-channel-id = <0>;
            qcom,mdss-dsi-stream = <0>;
            qcom,mdss-dsi-panel-width = <1080>;
            qcom,mdss-dsi-panel-height = <2160>;
            qcom,mdss-pan-physical-width-dimension = <68>;
            qcom,mdss-pan-physical-height-dimension = <136>;
            qcom,mdss-dsi-h-front-porch = <108>;
            qcom,mdss-dsi-h-back-porch = <60>;
            qcom,mdss-dsi-h-pulse-width = <12>;
            qcom,mdss-dsi-h-sync-skew = <0>;
            qcom,mdss-dsi-v-back-porch = <33>;
            qcom,mdss-dsi-v-front-porch = <6>;
            qcom,mdss-dsi-v-pulse-width = <4>;
            qcom,mdss-dsi-h-left-border = <0>;
            qcom,mdss-dsi-h-right-border = <0>;
            qcom,mdss-dsi-v-top-border = <0>;
            qcom,mdss-dsi-v-bottom-border = <0>;
            qcom,mdss-dsi-bpp = <24>;
            qcom,mdss-dsi-underflow-color = <0xff>;
            qcom,mdss-dsi-border-color = <0>;
            qcom,mdss-dsi-h-sync-pulse = <0>;
            qcom,mdss-dsi-traffic-mode = "burst_mode";
            qcom,mdss-dsi-bllp-eof-power-mode;
            qcom,mdss-dsi-bllp-power-mode;
            qcom,mdss-dsi-lane-0-state;
            qcom,mdss-dsi-lane-1-state;
            qcom,mdss-dsi-lane-2-state;
            qcom,mdss-dsi-lane-3-state;
            qcom,mdss-dsi-panel-timings = [e6 38 26 00 68 6e 2a 3c 44 03 04 00];
            qcom,mdss-dsi-t-clk-post = <0x0e>;
            qcom,mdss-dsi-t-clk-pre = <0x35>;
            qcom,mdss-dsi-bl-min-level = <1>;
            qcom,mdss-dsi-bl-max-level = <4095>;
            qcom,mdss-dsi-dma-trigger = "trigger_sw";
            qcom,mdss-dsi-mdp-trigger = "none";
            qcom,mdss-dsi-on-command = [
                39 01 00 00 46 00 02 11 00
                29 01 00 00 00 00 02 B0 04
                29 01 00 00 00 00 02 D6 01
                29 01 00 00 00 00 02 ea 0a
                39 01 00 00 00 00 02 51 ff
                39 01 00 00 00 00 02 53 2c
                29 01 00 00 00 00 1A CE 55 40 56 6E 87 95 a0 b0 c0 c2 c9 ce df e3 e4 ec FF 04 00 00 04 46 04 69 5A
                39 01 00 00 00 00 02 55 00
                39 01 00 00 00 00 02 35 00
                39 01 00 00 14 00 02 29 00
            ];
            qcom,mdss-dsi-off-command = [
                05 01 00 00 14 00 02 28 00
                05 01 00 00 78 00 02 10 00
            ];
            qcom,mdss-dsi-on-command-state = "dsi_lp_mode";
            qcom,mdss-dsi-off-command-state = "dsi_hs_mode";
            qcom,mdss-dsi-bl-pmic-control-type = "bl_ctrl_wled";
            qcom,mdss-dsi-reset-sequence = <1 1>, <0 5>, <1 35>;
            qcom,mdss-dsi-tx-eot-append;
            qcom,mdss-dsi-post-init-delay = <1>;
            qcom,ulps-enabled;
            qcom,panel-allow-phy-poweroff;
            qcom,mdss-dsi-panel-status-command = [06 01 00 01 05 00 01 0A];
            qcom,mdss-dsi-panel-status-command-state = "dsi_hs_mode";
            qcom,mdss-dsi-panel-status-check-mode = "reg_read";
            qcom,mdss-dsi-panel-status-read-length = <1>;
            qcom,mdss-dsi-panel-status-value = <0x1c>;
            qcom,mdss-dsi-panel-max-error-count = <3>;
        };
    };
};

I'm encountering the same issue even with the latest DTC, are there any workarounds?

[strongtz]

the latest DTC does solve the problem for me

[myryk31415]

I installed pylibfdt and libfdt from the dtc main / master branches but both times it says
ImportError: .../.venv/lib64/python3.11/site-packages/libfdt-1.7.2-py3.11-linux-x86_64.egg/_libfdt.cpython-311-x86_64-linux-gnu.so: undefined symbol: fdt_setprop_placeholder_namelen while trying to import _libfdt

Maybe it didn't install libfdt correctly, I'll try again to see if the log gives more information

Edit: Cherry-picking only the specific commit onto the 1.7.2 branch worked :)