IMX8MP - cannot set HDMI resolution

[KenBCHu]

Hi,

I have some problem about HDMI resolution. Anyone can give a suggestion about this? Thanks in advance! 

I tried to setup bootargs as below Monitor-not-working :

After boot completed, I tried some commands but it showed 800x600 in HDMI resolution.

Imx8mp settings:

MACHINE=imx8mp-lpddr4-evk

DISTRO=fsl-imx-xwayland

OS: imx-linux-kirkstone imx-5.15.71-2.2.0.xml

[Bio_TICFSL]

Hello,

The EDID of the monitor is being received and stored in /sys/class/drm/card0-HDMI-A-1/edid (attached).  Here are the supported modes of the monitor per the received EDID:

  Established Timings I & II:
    IBM     :   720x400    70.082 Hz   9:5    31.467 kHz  28.320 MHz
    DMT 0x04:   640x480    59.940 Hz   4:3    31.469 kHz  25.175 MHz
    Apple   :   640x480    66.667 Hz   4:3    35.000 kHz  30.240 MHz
    DMT 0x05:   640x480    72.809 Hz   4:3    37.861 kHz  31.500 MHz
    DMT 0x06:   640x480    75.000 Hz   4:3    37.500 kHz  31.500 MHz
    DMT 0x08:   800x600    56.250 Hz   4:3    35.156 kHz  36.000 MHz
    DMT 0x09:   800x600    60.317 Hz   4:3    37.879 kHz  40.000 MHz
    DMT 0x0a:   800x600    72.188 Hz   4:3    48.077 kHz  50.000 MHz
    DMT 0x0b:   800x600    75.000 Hz   4:3    46.875 kHz  49.500 MHz
    DMT 0x10:  1024x768    60.004 Hz   4:3    48.363 kHz  65.000 MHz
    DMT 0x11:  1024x768    70.069 Hz   4:3    56.476 kHz  75.000 MHz
    DMT 0x12:  1024x768    75.029 Hz   4:3    60.023 kHz  78.750 MHz

as mentioned here:

https://community.nxp.com/t5/i-MX-Processors/HDMI-DRM-custom-resolution-and-clock-frequency/m-p/1180...

Regards

[KenBCHu]

Hi @Bio_TICFSL,

I would like to set HDMI resolution to 1280*720. 

Currently, I get nothing at /sys/class/drm/card1-HDMI-A-1/edid.

I checked the url you shared, and it seems to set more pixel clock in platform.

Is it necessary for IMX8mp platform? The code in the link is quite different from my current version. Is there an example about setting resolution to 1280x720?

Thanks.