From patchwork Mon Feb 20 19:01:16 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Reichl X-Patchwork-Id: 9583507 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7A617604A0 for ; Mon, 20 Feb 2017 19:08:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 72E712885C for ; Mon, 20 Feb 2017 19:08:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6451F2886A; Mon, 20 Feb 2017 19:08:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E7B642885C for ; Mon, 20 Feb 2017 19:08:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751457AbdBTTIp (ORCPT ); Mon, 20 Feb 2017 14:08:45 -0500 Received: from mail.horus.com ([78.46.148.228]:33482 "EHLO mail.horus.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751364AbdBTTIp (ORCPT ); Mon, 20 Feb 2017 14:08:45 -0500 X-Greylist: delayed 445 seconds by postgrey-1.27 at vger.kernel.org; Mon, 20 Feb 2017 14:08:44 EST Received: from [192.168.1.20] (194-118-126-157.adsl.highway.telekom.at [194.118.126.157]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "E-Mail Matthias Reichl", Issuer "HiassofT CA 2014" (verified OK)) by mail.horus.com (Postfix) with ESMTPS id 36AC56408F; Mon, 20 Feb 2017 20:01:17 +0100 (CET) Received: by camel2.lan (Postfix, from userid 1000) id 32B0B1C731C; Mon, 20 Feb 2017 20:01:16 +0100 (CET) Date: Mon, 20 Feb 2017 20:01:16 +0100 From: Matthias Reichl To: Vinod Koul , Stephen Warren , Lee Jones , Eric Anholt Cc: Martin Sperl , Clive Messer , dmaengine@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RESEND PATCH] dmaengine: bcm2835: Fix cyclic DMA period splitting Message-ID: <20170220190115.GB4170@camel2.lan> Mail-Followup-To: Matthias Reichl , Vinod Koul , Stephen Warren , Lee Jones , Eric Anholt , Martin Sperl , Clive Messer , dmaengine@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The code responsible for splitting periods into chunks that can be handled by the DMA controller missed to update total_len, the number of bytes processed in the current period, when there are more chunks to follow. Therefore total_len was stuck at 0 and the code didn't work at all. This resulted in a wrong control block layout and audio issues because the cyclic DMA callback wasn't executing on period boundaries. Fix this by adding the missing total_len update. Signed-off-by: Matthias Reichl Signed-off-by: Martin Sperl Tested-by: Clive Messer Reviewed-by: Eric Anholt --- drivers/dma/bcm2835-dma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index 80d35f7..599c218 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -253,8 +253,11 @@ static void bcm2835_dma_create_cb_set_length( */ /* have we filled in period_length yet? */ - if (*total_len + control_block->length < period_len) + if (*total_len + control_block->length < period_len) { + /* update number of bytes in this period so far */ + *total_len += control_block->length; return; + } /* calculate the length that remains to reach period_length */ control_block->length = period_len - *total_len;