machinekit on BBB - how to force enabled HDMI hardware from cmdline

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1

I’m getting going with LinuxCNC Machinekit on BBB but my first hiccup is that I can’t get HDMI hardware enabled. I have an HDMI-DVI cable and for whatever reason the hardware has to be told to turn on. With Angstrom I pass “video=HDMI-A-1:e” on optargs in uEnv.txt but default Debian in Machinekit doesn’t do it.

is there something I can do to force it on/enabled from the command line? I’ve tried shelling in with ssh -X then doing xrandr :0.0 --output HDMI1 --auto but it didn’t work.
I’m checking /sys/class/drm/card0-HDMI-A-1/enabled and when booting Angstrom without a display connected it states “enabled” as it should. Booting Machinekit it states “disabled”.

any ideas? Thanks.

Doug

2

First, are you sure the option is being passed to the kernel? What does
"cat /proc/cmdline" return?

Second, have you tried the 'e' flag while also specifying a resolution?
Try something like:

kms_force_mode=video=HDMI-A-1:1024x768@60e

...in /boot/uboot/uEnv.txt.

3

I had looked at it and overlooked what was the problem but you asking and my copy/paste made me realize I’d cat’ed it onto the capemgr.disable… mesg with a comma instead of separating it. It now works. Thanks for slap in the back of the head.

Doug

4

HI Doug
I’m running into the same problem here using beagleboard black running ubuntu-dsktop on a sd card the /sys/class/drm/card0-HDMI-A-1/enabled shows disabled
cat /proc/cmdline shows this

console=ttyO0,115200n8 video capemgr=capemgr.enable_partno=BB-BONELT-HDMI root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait

ubuntu@ubuntu-armhf:~$ cat /sys/devices/bone_capemgr.9/slots
0: 54:PF—
1: 55:PF—
2: 56:PF—
3: 57:PF—
4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G
5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI

can u show me your uenv file? thx i try to edit my uenv doesn’t work
best
jason

5

in the uEnv.txt file there’s a line starting with “optargs=”
Add to the end of that line:

" video=HDMI-A-1:e"

make sure there’s a space before the “video=…” and this should force the enabling of the HDMI port.

Doug

6

Thanks for the quick reply doug
i tried
mmcpart=2
optargs=fixrtc video=HDMI-A-1:e
uenvcmd=i2c mw 0x24 1 0x3e; kd=0; if test $mmcdev -eq 1; then mmc dev 0; if mmc$
loadfdt=load mmc ${mmcdev}:${mmcpart} ${fdtaddr} ${bootdir}/dtbs/${fdtfile}
loadimage=load mmc ${mmcdev}:${mmcpart} ${loadaddr} ${bootdir}/${bootfile}

and some other things still not working any other suggestions or did i did it wrong? thanks a lot
Best
jason

7

I tried
mmcpart=2
optargs=fixrtc video=HDMI-A-1:e capemgr.enable_partno=BB-BONELT-HDMI #importent change the line above
uenvcmd=i2c mw 0x24 1 0x3e; kd=0; if test $mmcdev -eq 1; then mmc dev 0; if mmc$
loadfdt=load mmc ${mmcdev}:${mmcpart} ${fdtaddr} ${bootdir}/dtbs/${fdtfile}
loadimage=load mmc ${mmcdev}:${mmcpart} ${loadaddr} ${bootdir}/${bootfile}

and it worked thanks
best jason

8

great to hear it works

Doug