Re: Kernel 6.5 ttyS1 hang with qemu (was Re: [OE-core] Summary of the remaining 6.5 kernel serial issue (and 6.5 summary)

[Tony Lindgren <tony@atomide.com>]

* Richard Purdie <richard.purdie@linuxfoundation.org> [231017 22:15]:
> On Tue, 2023-10-17 at 09:56 +0300, Tony Lindgren wrote:
> > * Richard Purdie <richard.purdie@linuxfoundation.org> [231016 08:10]:
> > > The port sometimes doesn't come up properly at boot.
> > > 
> > > To be clear, the "\n\n" from the qemu side into the port doesn't seem
> > > to help. The "echo helloB > /dev/ttyS1" inside the image does seem to
> > > wake it up. 
> > 
> > So if I understand correctly, this issue still happens with kernel patched
> > with commit 81a61051e0ce ("serial: core: Fix checks for tx runtime PM
> > state"), and the issue now only happens sometimes.
> 
> The issue has always been intermittent and it appeared to happen less
> frequently with 81a61051e0ce added but it was hard to know if I was
> imagining that.

Oh OK.

> > I wonder if the following additional change might help?
> 
> I've added it into testing and have not reproduced the failure with it
> applied yet, locally or on our autobuilder. We need to sort some
> release pieces which have been delayed by these issues and we're going
> with a workaround for that. Once that is built I can get back to
> testing this change more extensively, see if we can still provoke the
> issue or not. It may take a day or two of testing before we know with
> any certainty if the issue is resolved or not.

Thanks for the update, let's wait a few days and see then.

Regards,

Tony