I have an STM32MP157D-DK1 development board and have built a buildroot image using the bootlin buildroot-external-st (st_stm32mp157d_dk1_demo_defconfig) external build tree. I have an Acubrite 12" 1080p touchscreen monitor that I am trying to get working at the monitor's native 1920x1080 resolution for use with a QT5 application but it is not working.
The monitor works fine but is limited to 1280x720 resolution. Modetest does not report anything higher than 1280x720:
root@stm32mp1:~# modetest -M stm
Encoders:
id crtc type possible crtcs possible clones
31 38 DPI 0x00000001 0x00000001
Connectors:
id encoder status name size (mm) modes encoders
32 31 connected HDMI-A-1 250x140 5 31
modes:
index name refresh (Hz) hdisp hss hse htot vdisp vss vse vtot
#0 1280x720 60.00 1280 1390 1430 1650 720 725 730 750 74250 flags: phsync, pvsync; type: driver
#1 1280x720 50.00 1280 1720 1760 1980 720 725 730 750 74250 flags: phsync, pvsync; type: driver
#2 800x600 75.00 800 816 896 1056 600 601 604 625 49500 flags: phsync, pvsync; type: driver
#3 720x576 50.00 720 732 796 864 576 581 586 625 27000 flags: nhsync, nvsync; type: driver
#4 720x480 59.94 720 736 798 858 480 489 495 525 27000 flags: nhsync, nvsync; type: driver
If I use this monitor with Windows 10/11 or Ubuntu 22.04 on a desktop PC, 1080p is detected straight away. Same thing trying it on a Raspberry Pi running Raspbian (works straight away).
I also tried it with the starter image provided by ST (SD card provided with the dev kit that boots openst linux) and it also only detected 1280x720p.
I tried a few other 1080p monitors we have lying around the office and one of them worked (modetest showed a valid 1920 x 1080 resolution) and one of them didn't (modetest only showed 1280x720).
I'm not sure where to go from here. Any advice would be greatly appreciated.
Thanks
