From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32DB9C433E0 for ; Mon, 25 May 2020 20:48:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1218320776 for ; Mon, 25 May 2020 20:48:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388805AbgEYUsh (ORCPT ); Mon, 25 May 2020 16:48:37 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:34283 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388714AbgEYUsh (ORCPT ); Mon, 25 May 2020 16:48:37 -0400 X-Originating-IP: 50.39.163.217 Received: from localhost (50-39-163-217.bvtn.or.frontiernet.net [50.39.163.217]) (Authenticated sender: josh@joshtriplett.org) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id BB5162000D; Mon, 25 May 2020 20:48:29 +0000 (UTC) Date: Mon, 25 May 2020 13:48:27 -0700 From: Josh Triplett To: Vladimir Oltean Cc: Greg Kroah-Hartman , linux-serial@vger.kernel.org, jslaby@suse.com, andriy.shevchenko@linux.intel.com, lukas@wunner.de, heikki.krogerus@linux.intel.com, vigneshr@ti.com, lkml , fido_max@inbox.ru, radu-andrei.bulie@nxp.com Subject: Re: [PATCH] serial: 8250: probe all 16550A variants by default Message-ID: <20200525204827.GC445190@localhost> References: <20200525130238.3614179-1-olteanv@gmail.com> <20200525172815.GA445190@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Mon, May 25, 2020 at 09:52:54PM +0300, Vladimir Oltean wrote: > Hi Josh, > > On Mon, 25 May 2020 at 20:28, Josh Triplett wrote: > > > > On Mon, May 25, 2020 at 04:02:38PM +0300, Vladimir Oltean wrote: > > > On NXP T1040, the UART is typically detected as 16550A_FSL64. After said > > > patch, it gets detected as plain 16550A and the Linux console is > > > completely garbled and missing characters. > > > > Interesting that there's *new* powerpc hardware that needs these > > variants. I based the patch on the fact that, on x86 at least, hardware > > using these variants hasn't been made for a long time. > > > > In the hopes of preserving at least part of the benefit of the patch, > > could you please change it to `default y if !X86_64`? > > > > Why don't you add CONFIG_SERIAL_8250_16550A_VARIANTS=n in x86_64_defconfig? In general, it seems preferable to me when the defconfig files differ less from the defaults encoded in Kconfig. You're proposing a change to the default; could you please include one or the other additional change in your patch to preserve the behavior on x86_64? > > > drivers/tty/serial/8250/Kconfig | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig > > > index af0688156dd0..89c7ecb55619 100644 > > > --- a/drivers/tty/serial/8250/Kconfig > > > +++ b/drivers/tty/serial/8250/Kconfig > > > @@ -63,6 +63,7 @@ config SERIAL_8250_PNP > > > config SERIAL_8250_16550A_VARIANTS > > > bool "Support for variants of the 16550A serial port" > > > depends on SERIAL_8250 > > > + default y > > > help > > > The 8250 driver can probe for many variants of the venerable 16550A > > > serial port. Doing so takes additional time at boot. > > > -- > > > 2.25.1 > > > > > Thanks, > -Vladimir