Subject: 4.16 OMAP serial transmit corruption?

From: [email-masked] (Tony Lindgren)
Date: Mon, 16 Apr 2018 08:45:45 -0700

* Russell King - ARM Linux <[email-masked]> [180416 15:19]:
> Hi,
> 
> I'm not entirely sure what's going on, but I see corrupted characters
> with the serial console on the OMAP4430 SDP board.  During boot,
> everything seems fine, the problem appears to be userspace output.
> 
> For example, if I edit a file, then quit vi:
> 
> :q??%??B??Z?root at omap-4430sdp:~#

I don't think I've seen that one. What I've seen few times is
typing a key on the serial console echoing back the previous
character typed while the new character won't get displayed
until hitting keyboard again. Only rebooting the device seems
to solve this. This is with 4430 ES2.3 revision.

I wonder if we're missing some parts of errata i202 handling
in omap_8250_mdr1_errataset()?

Also, I'm seeing an issue where the UARTs won't idle on init
with 8250_omap driver if connected to the wl12xx bluetooth port
unless I write some data to the port first. It does not seem
to be related to the rts/cts lines being wired as I've tested
muxing them out of the way.

Regards,

Tony