Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751868AbZL1QIy (ORCPT ); Mon, 28 Dec 2009 11:08:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751740AbZL1QIw (ORCPT ); Mon, 28 Dec 2009 11:08:52 -0500 Received: from mga02.intel.com ([134.134.136.20]:43800 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751711AbZL1QIv convert rfc822-to-8bit (ORCPT ); Mon, 28 Dec 2009 11:08:51 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.47,463,1257148800"; d="scan'208";a="582574951" From: "Sosnowski, Maciej" To: "Williams, Dan J" CC: "stable@kernel.org" , "linux-raid@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Mon, 28 Dec 2009 16:08:47 +0000 Subject: RE: [PATCH 1/3] ioat3: fix p-disabled q-continuation Thread-Topic: [PATCH 1/3] ioat3: fix p-disabled q-continuation Thread-Index: AcqDZqmseKv08O5pSPeQk12u/Yr5gwEcUR9g Message-ID: <129600E5E5FB004392DDC3FB599660D7CB3710B9@irsmsx504.ger.corp.intel.com> References: <20091223002518.32335.27768.stgit@dwillia2-linux.ch.intel.com> <20091223002555.32335.85860.stgit@dwillia2-linux.ch.intel.com> In-Reply-To: <20091223002555.32335.85860.stgit@dwillia2-linux.ch.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1035 Lines: 21 Williams, Dan J wrote: > When continuing a pq calculation the driver needs 3 extra sources. The > driver can perform a 3 source calculation with a single descriptor, but > needs an extended descriptor to process up to 8 sources in one > operation. However, in the p-disabled case only one extra source is > needed. When continuing a p-disabled operation there are occasions > (i.e. 0 < src_cnt % 8 < 3) where the tail operation does not need an > extended descriptor. Properly account for this fact otherwise invalid > 'dmacount' values will be written to hardware usually causing the > channel to halt with 'invalid descriptor' errors. > > Cc: > Signed-off-by: Dan Williams > --- Acked-by: Maciej Sosnowski -- 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/