Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752695AbbDCQ6B (ORCPT ); Fri, 3 Apr 2015 12:58:01 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:32838 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbbDCQ55 (ORCPT ); Fri, 3 Apr 2015 12:57:57 -0400 MIME-Version: 1.0 In-Reply-To: <551E6D61.7000501@hurleysoftware.com> References: <1425932842-21812-1-git-send-email-peter@hurleysoftware.com> <1425932842-21812-12-git-send-email-peter@hurleysoftware.com> <551CB5DF.1010108@hurleysoftware.com> <551D6EEA.6050704@hurleysoftware.com> <551E6D61.7000501@hurleysoftware.com> Date: Fri, 3 Apr 2015 09:57:56 -0700 X-Google-Sender-Auth: eQbjAy4z99VTJMx9huOhDI4vcJ0 Message-ID: Subject: Re: [PATCH v3 -next 11/11] serial: 8250_early: Remove setup_early_serial8250_console() From: Yinghai Lu To: Peter Hurley , Andrew Morton , Greg Kroah-Hartman , Linux Kernel Mailing List Cc: Jiri Slaby , Rob Herring , "linux-serial@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2206 Lines: 69 On Fri, Apr 3, 2015 at 3:37 AM, Peter Hurley wrote: > On 04/02/2015 10:38 PM, Yinghai Lu wrote: >> On Thu, Apr 2, 2015 at 5:22 PM, Yinghai Lu wrote: >> >>>>>> still have another problem. >>>>>> when using console=uart8250,io,0x3f8 >>>>>> it works as earlycon at first. >>>>>> but after handover to normal console >>>>>> it will revert back to 9600 again. >>>>> >>>>> this regression should be caused by: >>>>> >>>>> commit c7cef0a84912cab3c9df8949b034e4aa62982ec9 >>>>> Author: Peter Hurley >>>>> Date: Mon Mar 9 16:27:12 2015 -0400 >>>>> >>>>> console: Add extensible console matching >>>> >>> So your whole patchset will need the first patch ? >>> >>> or can you just drop the first one patch ? >> >> Please check attached patch that fix regresion by. commit c7cef0a849 >> ("console: Add extensible console matching") >> >> or you have better way? > > Please re-read my first response to this problem. > > Also, this expectation is an impediment when adding support for other > 8250-like designs that don't have the same 8250 divisor registers > (ie., _every_ new design). To properly support this requirement for > just the existing 8250 hardware will require special probe_baud() > functions for: dw_8250, intel byt, intel mid, omap_8250, exar 17v35 series, > omap 1510. But you can not break old setup! old behavior: console=uart8250,io,0x3f8 when bootloader or firmware has 115200 used already, earlycon, and console all keep 115200. Now with your change, earlycon will use 115200 still, but console will switch to 9600. > > Is specifying the line speed on the command line really a burden? > Yes. We have two setups, and two BIOS versions. product version is using 9600 and devel/debug is using 115200. This is a regression, and must be addressed. Greg, Please don't send merge request for tty-next to Linus before this regression get resolved. Thanks Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/