Re: Raspberry Pi 4

[email protected]
Newsgroups gmane.os.plan9.general
Message-ID <[email protected]>
> Thanks, I'll take a look at this.  Have you seen any pi4 h/w docs
> or have you been working just from linux drivers?

no, i wish. only reading linux source and deciphering device tree
mazes. :(

> I've been stalled on getting ether4330 to initialise.  Putting
> some coherence() calls into emmc.c helped (I don't like
> out-of-order cpus) but I keep getting spurious interrupt 1023
> followed by watchdog reboot.

i dont know anything about the 4330.

i think theres a bug with the dma code tho. you actually need to
invalidate caches *AFTER* the hw completed because the
core can speculatively prefetch memory and bring it into the
cache before the hardware is done writing memory. iirc the
code just cleans/invalidates BEFORE issuing the dma operation.

> Do you have the sdcard working?  According to a pi engineer,
> the new emmc controller is sdhci compliant so it shouldn't
> be hard.

i have not tried sdcard yet.

--
cinap
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