Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752445AbbG2PHi (ORCPT ); Wed, 29 Jul 2015 11:07:38 -0400 Received: from down.free-electrons.com ([37.187.137.238]:46820 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750803AbbG2PHf (ORCPT ); Wed, 29 Jul 2015 11:07:35 -0400 Date: Wed, 29 Jul 2015 17:07:33 +0200 From: Alexandre Belloni To: Andy Shevchenko Cc: Cyrille Pitchen , Nicolas Ferre , Greg Kroah-Hartman , wenyou.yang@atmel.com, "ludovic.desroches" , leilei.zhao@atmel.com, josh.wu@atmel.com, "linux-serial@vger.kernel.org" , "linux-kernel@vger.kernel.org" , linux-arm Mailing List , devicetree , Kumar Gala , ijc+devicetree , Mark Rutland , Pawel Moll , Rob Herring Subject: Re: [PATCH v4 4/5] tty/serial: at91: add support to FIFOs Message-ID: <20150729150733.GB6073@piout.net> References: <4d8e90ad2cbb0d020dae4a4806ffc8864b5b22b6.1435842688.git.cyrille.pitchen@atmel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1527 Lines: 38 Hi Andy, On 29/07/2015 at 17:51:38 +0300, Andy Shevchenko wrote : > On Thu, Jul 2, 2015 at 4:18 PM, Cyrille Pitchen > wrote: > > Depending on the hardware, TX and RX FIFOs may be available. The RX > > FIFO can avoid receive overruns, especially when DMA transfers are > > not used to read data from the Receive Holding Register. For heavy > > system load, The CPU is likely not be able to fetch data fast enough > > from the RHR. > > This patch broke avr32 console (as seen in today's linux-next) on ATNGW100. > Reverting helps. I'm pretty sure the issue is in 8 bit vs. 32 bit I/O access. > > # uname -a > Linux buildroot 4.2.0-rc4-next-20150729+ #97 Wed Jul 29 17:50:11 EEST > 2015 avr32 GNU/Linux > > Do you, guys, have that board (NGW100) or it's officially unsupported? > If the latter is the case I would really appreciate if you remove the > support from the kernel side. > The main issue here is that the main atmel arm developers don't have access to any avr32 board. I'd say that everything that is done is best effort to not break avr32 but it is not tested at all. Don't hesitate to submit patches when something breaks... -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- 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/