Imx8mqevk yocto 5.4.70 custom resolution

[thinhpham]

Hi experts,

I'm using imx8m-evk, I have bought waveshare 7inch hdmi (c) model. This screen supports fixed resolution 1024x600, but from drm/fb0/modes, I could not find this resolution. I can see the nxp logo at boot time, but it does not show the penguin, loading screen and main desktop. I suppose a reason is from not supported resolution in yocto build. How can I add a custom resolution to my build?

Thank you!

[joanxie]

try to add 1024x600 in the drm_dmt_modes ofdrm_edid.c according to your display spec,

"https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/gpu/drm/drm_edid.c?h=imx_5.4.70_2....

after boot up, check the log file if the board detect the display or not

[thinhpham]

Hi joanxie,

I added several settings in

linux-imx/drivers/gpu/drm/drm_edid.c

// In drm_dmt_modes
/* 0x59 - 1024x600@60Hz */
{ DRM_MODE("1024x600", DRM_MODE_TYPE_DRIVER, 54000, 1024, 1072,
	   1168, 1312, 0, 600, 603, 613, 626, 0,
	   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NVSYNC) },

// In edid_cea_modes
/* 108 - 1024x600@60Hz 16:9 */
{ DRM_MODE("1024x600", DRM_MODE_TYPE_DRIVER, 54000, 1024, 1072,
	1168, 1312, 0, 600, 603, 613, 626, 0,
	DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC),
	.vrefresh = 60, .picture_aspect_ratio = HDMI_PICTURE_ASPECT_16_9, },

sources/meta-imx/meta-bsp/recipes-graphics/wayland/weston-init/weston.ini

[output] 
name=HDMI-A-1
mode=1024x600@60

But still no 1024x600 resolution in cat /sys/class/drm/card0-HDMI-A-1/modes

Thank you!

[joanxie]

could you send the log file to me? how did you connect the hdmi to imx8mq board? via dcss or lcdif?

[thinhpham]

Sorry, I'm new to embedded development so could you please tell me which log file do you want to check? Btw, my screen connected to hdmi port on evk board directly.

[joanxie]

when the board boot up, you should get print information from the uart debug port, send this information to me

[thinhpham]

Hi, sorry for delay. I have struggled to get the log for awhile. Here it is, please check!

[joanxie]

it seems that this isn't complete log file, pls send the information start of the board boot up

[thinhpham]

Sorry, I captured the log file again, please check it. Thank you!

[joanxie]

did you use dcss or lcdif? refer to the log file, you use dcss, right? which dts file do you use? or send your dts file to me