From patchwork Wed Nov 25 21:34:42 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ondrej Zary X-Patchwork-Id: 7703041 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6063ABF90C for ; Wed, 25 Nov 2015 21:35:22 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9DE862082E for ; Wed, 25 Nov 2015 21:35:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C032F20826 for ; Wed, 25 Nov 2015 21:35:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752508AbbKYVfD (ORCPT ); Wed, 25 Nov 2015 16:35:03 -0500 Received: from ns.gsystem.sk ([62.176.172.50]:42447 "EHLO gsystem.sk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751481AbbKYVfB (ORCPT ); Wed, 25 Nov 2015 16:35:01 -0500 Received: from stip-static-68.213-81-217.telecom.sk ([213.81.217.68] helo=gsql.ggedos.sk) by gsystem.sk with esmtpsa (TLS1.1:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1a1hiK-00072u-OH; Wed, 25 Nov 2015 22:34:56 +0100 From: Ondrej Zary To: Finn Thain , Michael Schmitz , linux-m68k@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 72/71] ncr5380: Fix pseudo-DMA Date: Wed, 25 Nov 2015 22:34:42 +0100 Message-Id: <1448487282-31766-1-git-send-email-linux@rainbow-software.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <20151118083455.331768508@telegraphics.com.au> References: <20151118083455.331768508@telegraphics.com.au> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Pseudo-DMA (PDMA) has been broken for ages, resulting in hangs on 53C400-based cards. According to 53C400 datasheet, PDMA transfer length must be a multiple of 128. Check if that's true and use PIO if it's not. This makes PDMA work on 53C400 (Canon FG2-5202). Signed-off-by: Ondrej Zary --- drivers/scsi/g_NCR5380.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c index 0daffe2..a9a237f 100644 --- a/drivers/scsi/g_NCR5380.c +++ b/drivers/scsi/g_NCR5380.c @@ -703,6 +703,10 @@ static int generic_NCR5380_dma_xfer_len(struct scsi_cmnd *cmd) !(cmd->SCp.this_residual % transfersize)) transfersize = 32 * 1024; + /* 53C400 datasheet: non-modulo-128-byte transfers should use PIO */ + if (transfersize % 128) + transfersize = 0; + return transfersize; }