On Sun, Apr 17, 2022 at 11:52 AM Vasily Khoruzhick anarsoul@gmail.com wrote:
On Sun, Apr 17, 2022 at 9:15 AM Torsten Duwe duwe@lst.de wrote:
Align the power-up sequence with the known-good procedure documented in [1]: un-swap dvdd12 and dvdd25, and allow a little extra time for them to settle before de-asserting reset.
Hi Torsten,
Interesting find! I tried to fix the issue several times by playing with the delays to no avail.
What's interesting, ANX6345 datasheet allows DVDD12 to come up either earlier or later than DVDD25 with the delay of T1 (2ms typical) between them, and actually bringing up DVDD12 first works fine in u-boot.
The datasheet also requires reset to be deasserted no earlier than T2 (2-5ms) after all the rails are stable.
Another thing it mentions is that the system clock must be stable for T3 (1-3ms) before reset is deasserted, T3 is already a part of T2, however it cannot be gated on Pinebook, see [1], page 15
The change looks good to me, but I'll need some time to actually test it. If you don't hear from me for longer than a week please ping me.
Your change doesn't fix the issue for me. Running "xrandr --output eDP-1 --off; xrandr --output eDP-1 --auto" in a loop triggers the issue pretty quickly even with the patch.