Hello Paul,

26.07.2021, 19:51, "Paul Fertser" <fercerpav@gmail.com>:

On Mon, Jul 26, 2021 at 07:42:22PM +0300, Konstantin Klubnichkin wrote:
Thank you for this patch, I've tried this (UART1 <->UART3 routing), but this
just doesn't work on my hardware, even POST is not available.
Probably only way is to ask Aspeedtech support to clarify this.

What's your hardware? On our board we have LPC connection between
AST2500 and Lewisburg PCH.

It's custom server developed for us, but we also have LPC between AST2500 and PCH, so there is no difference

If your UEFI is configuring SIRQ inContinuous mode (should be default I guess) then you might also want
this (even though VUART wouldn't be used with the configuration used

SIRQ polarity is something I didn't try, will do it. And yes, SIRQ bit is zero, but all other bits are also zero in that register, that confuses me.

by the patch I've sent earlier):

+diff --git a/arch/arm/boot/dts/aspeed-bmc-facebook-tiogapass.dts b/arch/arm/boot/dts/aspeed-bmc-facebook-tiogapass.dts
+index fffdb2b67c08..77233d360142 100644
+--- a/arch/arm/boot/dts/aspeed-bmc-facebook-tiogapass.dts
++++ b/arch/arm/boot/dts/aspeed-bmc-facebook-tiogapass.dts
+@@ -157,6 +157,7 @@
+
+ &vuart {
+ // VUART Host Console
++ aspeed,sirq-polarity-sense = <&syscon 0x70 25>;
+ status = "okay";
+ };
+

I suggest you try these two patches verbatim, this whole remapping
business is tricky so probably you've missed something in your earlier
tests.

It is probable because I don't patch U-Boot.

Instead I configure UART routing by direct writing to registers via /dev/mem (yes, I know that it's a bad practive, but it's development).

With the routing I have absolutely no data in BMC UARTs neither during POST nor is OS.

What I'm missing is how that routing works. Is it on-crystal or UART need to be routed to SoC pins thus TX/RX are connected via pins?

Now I'm trying to compare LPC registers from other vendor BMC on the same platform with what we have in OpenBMC, may be this will show some differences.

--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:fercerpav@gmail.com

Best regards,

Konstantin Klubnichkin,

lead firmware engineer,

server hardware R&D group,

Yandex Moscow office.

tel: +7-903-510-33-33