linuxcnc-2.8.0-pi4.img - no USB on raspberry pi 4 - 8GB & 2GB

jfselcnc wrote: Is there any advantage of now using the new 2.8.1 img? .

Not if what you have is working.

The changes include a kernel version that works with the variants that have no eeprom for the USB system and the 4GB limit pre-applied.

I hadn't seen that, I was still using 2.8.0, it worked fine with my earlier pi4...

Just found linuxcnc-2.8.1-pi4.img and it seems to work perfectly, thank you

I have just tested the SD image on my new RPi400. Lateny (Servo+base) is ~ 75000 as it comes out of the box.

Now I moved it from SD to a 8GB Kingston USB3 thumbdrive - write access is a bit on the slow side. I moved /var/tmp /tmp and /var/log to tmpfs, swapped from Debian to Devuan, killed anything GNOME and installed TDE. This brought latency down to 65000.

Now I disabled BT + WIFI + audio. Latency is <50000 after an hour testing.

twoflowers wrote: I have just tested the SD image on my new RPi400

_Which_ SD image?

I found that Linuxcnc-2.8.1-pi4.img didn't work on my Pi400.

Exactly that image works here. But as I said, I did not put it on the SD-card but a USB thumbdrive plugged into the USB3 port. When I remove the 3GB limit, it does not boot (USB is unavailable), but otherwise it just works.

Oh, and it does not boot on the RPI3+

... but there is something fishy with the kernel. I see these in the logfile - and I can imagine that you cannot boot reliably from mmc:

[ 77.284159] mmc0: Timeout waiting for hardware cmd interrupt.
[ 77.289904] mmc0: sdhci: ============ SDHCI REGISTER DUMP ===========
[ 77.296338] mmc0: sdhci: Sys addr: 0x00000000 | Version: 0x00001002
[ 77.302771] mmc0: sdhci: Blk size: 0x00000000 | Blk cnt: 0x00000000
[ 77.309204] mmc0: sdhci: Argument: 0x00000000 | Trn mode: 0x00000000
[ 77.315637] mmc0: sdhci: Present: 0x1fff0001 | Host ctl: 0x00000001
[ 77.322070] mmc0: sdhci: Power: 0x0000000f | Blk gap: 0x00000080
[ 77.328502] mmc0: sdhci: Wake-up: 0x00000000 | Clock: 0x0000f447
[ 77.334935] mmc0: sdhci: Timeout: 0x00000000 | Int stat: 0x00000000
[ 77.341367] mmc0: sdhci: Int enab: 0x00ff1003 | Sig enab: 0x00ff1003
[ 77.347800] mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
[ 77.354232] mmc0: sdhci: Caps: 0x45ee6432 | Caps_1: 0x0000a525
[ 77.360664] mmc0: sdhci: Cmd: 0x00000502 | Max curr: 0x00080008
[ 77.367096] mmc0: sdhci: Resp[0]: 0x00000000 | Resp[1]: 0x00000000
[ 77.373529] mmc0: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000
[ 77.379961] mmc0: sdhci: Host ctl2: 0x00000000
[ 77.384396] mmc0: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x00000000
[ 77.390828] mmc0: sdhci: ============================================