Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934334Ab3FSLWq (ORCPT ); Wed, 19 Jun 2013 07:22:46 -0400 Received: from hqemgate03.nvidia.com ([216.228.121.140]:1376 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934067Ab3FSLWp (ORCPT ); Wed, 19 Jun 2013 07:22:45 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Wed, 19 Jun 2013 04:22:43 -0700 Message-ID: <51C19485.3000708@nvidia.com> Date: Wed, 19 Jun 2013 19:22:45 +0800 From: Wei Ni User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Rob Herring , CC: "linux-kernel@vger.kernel.org" , , , Subject: Re: [RFC PATCH 1/3] pstore-ram: use write-combine mappings Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 994 Lines: 25 > Atomic operations are undefined behavior on ARM for device or strongly > ordered memory types. So use write-combine variants for mappings. This > corresponds to normal, non-cacheable memory on ARM. For many other > architectures, this change should not change the mapping type. Hi, all I have met this problems on tegra soc. I tried to use pstore-ram, but the system will hang up when run the atomic_cmpxchg() in the buffer_start_add() or buffer_size_add(), whatever I use iomapped or vmapped regions. I tried to apply this patch set, it was failed with vmap, but if use iomapped rgiions, the ldrex/strex can work on this memory, and the ramoops driver can work. Does there have any updates for this issue? Or how can I debug it? Thanks. Wei. -- 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/