From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753253Ab3LFCm2 (ORCPT ); Thu, 5 Dec 2013 21:42:28 -0500 Received: from zimbra.real-time.com ([63.170.91.9]:45870 "EHLO zimbra.real-time.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751500Ab3LFCm0 (ORCPT ); Thu, 5 Dec 2013 21:42:26 -0500 Date: Fri, 6 Dec 2013 13:42:11 +1100 From: James Cameron To: Sergei Ianovich Cc: linux-kernel@vger.kernel.org, "open list:OPEN FIRMWARE AND..." , Heikki Krogerus , Russell King , Greg Kroah-Hartman , Ralf Baechle , Rob Herring , Haojian Zhuang , "open list:SERIAL DRIVERS" , Grant Likely , Andrew Morton , John Crispin , Jiri Slaby , "moderated list:ARM PORT" , Zhou Zhu Subject: Re: [PATCH] serial: rewrite pxa2xx-uart to use 8250_core Message-ID: <20131206024211.GK16425@us.netrek.org> References: <20131205043544.GA28580@kroah.com> <1386286149-2855-1-git-send-email-ynvich@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1386286149-2855-1-git-send-email-ynvich@gmail.com> Organization: Netrek Vanilla Server Dictator User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 06, 2013 at 03:28:37AM +0400, 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. [...] > +/* Uart divisor latch write */ > +static void serial_pxa_dl_write(struct uart_8250_port *up, int value) > +{ > + serial_out(up, UART_DLL, value & 0xff); > + serial_out(up, UART_DLM, value >> 8 & 0xff); > +} This is a change. drivers/tty/serial/pxa.c did read back UART_DLL as an errata work around: > - /* > - * work around Errata #75 according to Intel(R) PXA27x Processor Family > - * Specification Update (Nov 2005) > - */ > - dll = serial_in(up, UART_DLL); > - WARN_ON(dll != (quot & 0xff)); If this is no longer needed, serial_pxa_dl_write can be removed because it is same as default_serial_dl_write. I did not check the other errata work arounds. -- James Cameron http://quozl.linux.org.au/ From mboxrd@z Thu Jan 1 00:00:00 1970 From: quozl@laptop.org (James Cameron) Date: Fri, 6 Dec 2013 13:42:11 +1100 Subject: [PATCH] serial: rewrite pxa2xx-uart to use 8250_core In-Reply-To: <1386286149-2855-1-git-send-email-ynvich@gmail.com> References: <20131205043544.GA28580@kroah.com> <1386286149-2855-1-git-send-email-ynvich@gmail.com> Message-ID: <20131206024211.GK16425@us.netrek.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Dec 06, 2013 at 03:28:37AM +0400, 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. [...] > +/* Uart divisor latch write */ > +static void serial_pxa_dl_write(struct uart_8250_port *up, int value) > +{ > + serial_out(up, UART_DLL, value & 0xff); > + serial_out(up, UART_DLM, value >> 8 & 0xff); > +} This is a change. drivers/tty/serial/pxa.c did read back UART_DLL as an errata work around: > - /* > - * work around Errata #75 according to Intel(R) PXA27x Processor Family > - * Specification Update (Nov 2005) > - */ > - dll = serial_in(up, UART_DLL); > - WARN_ON(dll != (quot & 0xff)); If this is no longer needed, serial_pxa_dl_write can be removed because it is same as default_serial_dl_write. I did not check the other errata work arounds. -- James Cameron http://quozl.linux.org.au/