topic Re: IMX8MP - cannot set HDMI resolution in i.MX Processors

IMX8MP - cannot set HDMI resolution

KenBCHu — Fri, 02 Feb 2024 08:52:06 GMT

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

Re: IMX8MP - cannot set HDMI resolution

Bio_TICFSL — Fri, 02 Feb 2024 15:43:59 GMT

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/1180662

Regards

Re: IMX8MP - cannot set HDMI resolution

KenBCHu — Mon, 05 Feb 2024 02:38:55 GMT

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.