Re: [PATCH 5.10 044/390] serial: 8250: Let drivers request full 16550A feature probing

From: Greg Kroah-Hartman
Date: Tue Oct 25 2022 - 09:16:42 EST


On Mon, Oct 24, 2022 at 07:27:10PM +0200, Pavel Machek wrote:
> Hi!
>
> > From: Maciej W. Rozycki <macro@xxxxxxxxxxx>
> >
> > commit 9906890c89e4dbd900ed87ad3040080339a7f411 upstream.
> >
> > A SERIAL_8250_16550A_VARIANTS configuration option has been recently
> > defined that lets one request the 8250 driver not to probe for 16550A
> > device features so as to reduce the driver's device startup time in
> > virtual machines.
> >
> > Some actual hardware devices require these features to have been fully
> > determined however for their driver to work correctly, so define a flag
> > to let drivers request full 16550A feature probing on a device-by-device
> > basis if required regardless of the SERIAL_8250_16550A_VARIANTS option
> > setting chosen.
>
> As far as I can see, the UPF_FULL_PROBE is never set in 5.10.150 tree,
> so we should not need it there.

Ah, yes, it was tagged wrong. I'll go drop this now, it's only needed
in 5.15.y

thanks,

greg k-h