Hi Nikolaus,
One last PCB question. Is R2102 populated on production boards, if so, how long is the trace from R2102 to the connector? If it is non-trivial then removing R2102 could reduce the noise picked up by the clock.
Best
David
On Fri, 2020-07-31 at 21:12 +0100, David Shah wrote:
On Fri, 2020-07-31 at 20:05 +0200, Michael Mrozek wrote:
Am Freitag, den 31.07.2020, 19:48 +0200 schrieb H. Nikolaus Schaller:
Just FYI: As daveshah can now reproduce the issue on the uEVM, we're trying the original SDDK from TI. With old kernel, fully working AESS, etc.
Tested this now and it still glitches when I glitch the clock. Of course, this doesn't necessarily replicate whatever is going on in the Pyra. And the glitching is slightly different, same volume but slightly more "white" and with slightly more of the original of the original stream still coming through - so I guess either the old config or the AESS does change something.
If we can glitch it there as well, then we could still try to add the inverter - but adding the inverter to the 500 produced CPU boards would't be possible, I guess.
No, not if you want to retain your sanity :) But easy enough for me to buy an inverter and solder it to the uEVM just for closure on the issue if nothing else.
If it's not possible to glitch it with TIs older OS, it's likely we can somehow fix it.
What could be interesting is to compare the sound/soc/ti/omap- mcpdm.c driver as well as omap-abe-twl6040.c between v4.7 and v5.x. It is not even necessary to compare the letux versions since the old kernel does not have any private patches and we tested the newer one without letux (aess) patches.
It is a little more tricky to do that diff because the files have been moved to new locations.
Am 31.07.2020 um 19:29 schrieb H. Nikolaus Schaller < hns@goldelico.com>:
The kernel tree is here:
https://git.goldelico.com/?p=letux-kernel.git;a=shortlog;h=refs/heads/letux-...
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