From patchwork Wed Jun 17 14:22:26 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ludovic Desroches X-Patchwork-Id: 6626431 Return-Path: X-Original-To: patchwork-linux-arm@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 D3725C0020 for ; Wed, 17 Jun 2015 14:25:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1281C20877 for ; Wed, 17 Jun 2015 14:25:09 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2FFFE20876 for ; Wed, 17 Jun 2015 14:25:08 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Z5EEp-0006TB-9T; Wed, 17 Jun 2015 14:22:47 +0000 Received: from eusmtp01.atmel.com ([212.144.249.242]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Z5EEh-0006OB-OO for linux-arm-kernel@lists.infradead.org; Wed, 17 Jun 2015 14:22:43 +0000 Received: from ibiza.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.30) with Microsoft SMTP Server id 14.3.235.1; Wed, 17 Jun 2015 16:22:12 +0200 From: Ludovic Desroches To: , , Subject: [PATCH] dmaengine: at_xdmac: fix bug about channel configuration Date: Wed, 17 Jun 2015 16:22:26 +0200 Message-ID: <1434550946-27750-1-git-send-email-ludovic.desroches@atmel.com> X-Mailer: git-send-email 2.2.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150617_072239_981430_097F6479 X-CRM114-Status: GOOD ( 11.34 ) X-Spam-Score: -2.9 (--) Cc: vinod.koul@intel.com, maxime.ripard@free-electrons.com, Ludovic Desroches , nicolas.ferre@atmel.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 When using descriptor view 2 or higher, we don't write the configuration into AT_XDMAC_CC register because this configuration will be fetch from the descriptor. Unfortunately, the PROT bit is not updated with this method, we have to do it manually before enabling the channel. Signed-off-by: Ludovic Desroches --- drivers/dma/at_xdmac.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index cf1213d..52ca1cc 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -359,18 +359,19 @@ static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan, * descriptor view 2 since some fields of the configuration register * depend on transfer size and src/dest addresses. */ - if (at_xdmac_chan_is_cyclic(atchan)) { + if (at_xdmac_chan_is_cyclic(atchan)) reg = AT_XDMAC_CNDC_NDVIEW_NDV1; - at_xdmac_chan_write(atchan, AT_XDMAC_CC, first->lld.mbr_cfg); - } else if (first->lld.mbr_ubc & AT_XDMAC_MBR_UBC_NDV3) { + else if (first->lld.mbr_ubc & AT_XDMAC_MBR_UBC_NDV3) reg = AT_XDMAC_CNDC_NDVIEW_NDV3; - } else { - /* - * No need to write AT_XDMAC_CC reg, it will be done when the - * descriptor is fecthed. - */ + else reg = AT_XDMAC_CNDC_NDVIEW_NDV2; - } + /* + * Even if the register will be updated from the configuration in the + * descriptor when using view 2 or higher, the PROT bit won't be set + * properly. This bit can be modified only by using the channel + * configuration register. + */ + at_xdmac_chan_write(atchan, AT_XDMAC_CC, first->lld.mbr_cfg); reg |= AT_XDMAC_CNDC_NDDUP | AT_XDMAC_CNDC_NDSUP