Regression from patch 'tty: hvc: hvc_poll() break hv read loop'

[Nicholas Piggin]

On Tue, 4 Sep 2018 11:48:08 -0600
Jason Gunthorpe <jgg at mellanox.com> wrote:

> Hi Nicholas,
> 
> I am testing 4.19-rc2 and I see bad behavior with my qemu hvc0
> console..
> 
> Running interactive with qemu (qemu-2.11.2-1.fc28) on the console
> providing hvc0, using options like:
> 
>         -nographic
>         -chardev stdio,id=stdio,mux=on,signal=off
>         -mon chardev=stdio
> 	-device isa-serial,chardev=stdio
>         -device virtio-serial-pci
> 	-device virtconsole,chardev=stdio
> 
> I see the hvc0 console hang regularly, ie doing something like 'up
> arrow' in bash causes the hvc0 console to hang. Prior kernels worked
> OK.
> 
> Any ideas? I'm not familiar with this code.. Thanks!

Yes I have had another report, I'm working on a fix. Sorry it has taken
a while and thank you for the report.

Thanks,
Nick