Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753552AbbL2QvK (ORCPT ); Tue, 29 Dec 2015 11:51:10 -0500 Received: from smtp07.smtpout.orange.fr ([80.12.242.129]:53623 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753200AbbL2QvG (ORCPT ); Tue, 29 Dec 2015 11:51:06 -0500 X-ME-Helo: belgarion X-ME-Auth: amFyem1pay5yb2JlcnRAb3JhbmdlLmZy X-ME-Date: Tue, 29 Dec 2015 17:51:03 +0100 X-ME-IP: 92.136.207.223 From: Robert Jarzmik To: Heikki Krogerus , Sergei Ianovich Cc: linux-kernel@vger.kernel.org, James Cameron , Greg Kroah-Hartman , Russell King , Jiri Slaby , Andy Shevchenko , Arnd Bergmann , Joachim Eastwood , Sebastian Andrzej Siewior , Scott Wood , Paul Gortmaker , Paul Burton , Mans Rullgard , Ralf Baechle , Masahiro Yamada , Peter Hurley , "open list\:SERIAL DRIVERS" Subject: Re: [PATCH v6] serial: rewrite pxa2xx-uart to use 8250_core References: <1450897204-6839-1-git-send-email-ynvich@gmail.com> <1450970122-12869-1-git-send-email-ynvich@gmail.com> <20151229110643.GB19870@kuha.fi.intel.com> X-URL: http://belgarath.falguerolles.org/ Date: Tue, 29 Dec 2015 17:50:53 +0100 In-Reply-To: <20151229110643.GB19870@kuha.fi.intel.com> (Heikki Krogerus's message of "Tue, 29 Dec 2015 13:06:43 +0200") Message-ID: <8760zhfbbm.fsf@belgarion.home> User-Agent: Gnus/5.130008 (Ma Gnus v0.8) Emacs/24.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2639 Lines: 64 Heikki Krogerus writes: > On Thu, Dec 24, 2015 at 06:15:14PM +0300, Sergei Ianovich wrote: >> pxa2xx-uart was a separate uart platform driver. It was declaring >> the same device names and numbers as 8250 driver. As a result, >> it was impossible to use 8250 driver on PXA SoCs. >> >> Upon closer examination pxa2xx-uart turned out to be a clone of >> 8250_core driver. >> >> Workaround for Erratum #19 according to Marvel(R) PXA270M Processor >> Specification Update (April 19, 2010) is dropped. 8250_core reads >> from FIFO immediately after checking DR bit in LSR. >> >> The patch leaves the original SERIAL_PXA driver around. The original >> driver is just marked DEPRECATED in Kconfig and C source. When >> the original driver is considered safe to remove, no changes >> to SERIAL_8250 will be necessary. >> >> Compiling SERIAL_8250_CONSOLE and SERIAL_PXA_CONSOLE even without >> SERIAL_8250_PXA breaks console for SERIAL_PXA. For this reasons, the new >> and the original drivers are made mutually exclusive. >> >> Signed-off-by: Sergei Ianovich >> CC: Heikki Krogerus > > Reviewed-by: Heikki Krogerus Tested-by: Robert Jarzmik The tests were done on lubbock(pxa25x), mainstone(pxa27x) and zylonite(pxa3xx) boards. I don't expect any breakage in PXA architecture. There might be issues with : - arch/arm/mach-pxa/capc7117.c - arch/arm/mach-pxa/viper.c -arch/arm/mach-pxa/zeus.c (very small probability for this one) The mitigation plan if any concern arises is to fallback on the CONFIG_SERIAL_PXA configuration. I find a bit misleading this chunk, but I'm not very good at KConfig : config SERIAL_PXA - bool "PXA serial port support" + bool "PXA serial port support (DEPRECATED)" depends on ARCH_PXA || ARCH_MMP select SERIAL_CORE + select SERIAL_8250_PXA if SERIAL_8250=y + select SERIAL_PXA_NON8250 if !SERIAL_8250=y What bothers me a bit is that selecting this option has a different effect whether SERIAL_8250 is set or not. Somebody selecting the deprecated option obviously wants the old driver, but will be provided the new one if his config has SERIAL_8250 set. Maybe someone else can comment on this ... This apart, from pxa perspective, it's good to go. Cheers. -- Robert -- 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/