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Date:   Thu, 31 Mar 2022 08:12:00 +0100 (BST)
From:   "Maciej W. Rozycki" <macro@orcam.me.uk>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc:     Jiri Slaby <jirislaby@kernel.org>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] serial: 8250: Report which option to enable for
 blacklisted PCI devices
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On Sun, 27 Feb 2022, Maciej W. Rozycki wrote:

> > > We don't do this for any other driver subsystem, so why is it really
> > > needed?  What is so special about this driver that distros can't
> > > just enable all of the drivers and all is good?  What is keeping those
> > > drivers fromb eing enabled?
> > 
> >  My justification is we have a supposedly generic PCI 8250 UART driver, 
> > except it explicitly and silently refuses to handle a handful of devices 
> > chosen by their PCI IDs based on that they may have extra features, even 
> > though they are otherwise fully compatible with a generic 8250.
> 
>  Actually as it happens we do have a precedent too, as here's what I have 
> just spotted on my laptop by chance when hibernating:
> 
> psmouse serio1: synaptics: The touchpad can support a better bus than the too old PS/2 protocol. Make sure MOUSE_PS2_SYNAPTICS_SMBUS and RMI4_SMB are enabled to get a better touchpad experience.
> 
> (with a distribution kernel, so clearly whoever packaged that has not 
> enabled what might be needed).  Someone else wanted to be helpful too as 
> it seems.

 I have now posted v3 with these clarifications included in the change 
descriptions.  Please review.

  Maciej