From patchwork Fri Dec 19 16:18:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Jackson X-Patchwork-Id: 5520731 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 871819F30B for ; Fri, 19 Dec 2014 16:21:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AD09320148 for ; Fri, 19 Dec 2014 16:21:40 +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 DD16E2013A for ; Fri, 19 Dec 2014 16:21:39 +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 1Y20H0-00057Y-Kc; Fri, 19 Dec 2014 16:19:26 +0000 Received: from fw-tnat.cambridge.arm.com ([217.140.96.140] helo=cam-smtp0.cambridge.arm.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Y20GZ-0004n2-AY for linux-arm-kernel@lists.infradead.org; Fri, 19 Dec 2014 16:19:00 +0000 Received: from e106787-lin.cambridge.arm.com (e106787-lin.cambridge.arm.com [10.1.193.37]) by cam-smtp0.cambridge.arm.com (8.13.8/8.13.8) with ESMTP id sBJGIOTQ019527; Fri, 19 Dec 2014 16:18:25 GMT From: Andrew Jackson To: Jaroslav Kysela , Takashi Iwai Subject: [PATCH v3 1/5] ASoC: dwc: Ensure FIFOs are flushed to prevent channel swap Date: Fri, 19 Dec 2014 16:18:05 +0000 Message-Id: <8f40608d5665e80bfd3e9723784ec3bc2078e0d2.1418826016.git.Andrew.Jackson@arm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: In-Reply-To: References: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141219_081859_727142_F59C84D9 X-CRM114-Status: GOOD ( 11.10 ) X-Spam-Score: -0.0 (/) Cc: alsa-devel@alsa-project.org, Lars-Peter Clausen , Arnd Bergmann , linux-kernel@vger.kernel.org, Andrew Jackson , Liviu Dudau , Liam Girdwood , Rajeev Kumar , Mark Brown , linux-arm-kernel@lists.infradead.org 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_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 From: Andrew Jackson Flush the FIFOs when the stream is prepared for use. This avoids an inadvertent swapping of the left/right channels if the FIFOs are not empty at startup. Signed-off-by: Andrew Jackson --- sound/soc/dwc/designware_i2s.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c index f81e747..5c13303 100644 --- a/sound/soc/dwc/designware_i2s.c +++ b/sound/soc/dwc/designware_i2s.c @@ -263,6 +263,19 @@ static void dw_i2s_shutdown(struct snd_pcm_substream *substream, snd_soc_dai_set_dma_data(dai, substream, NULL); } +static int dw_i2s_prepare(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + i2s_write_reg(dev->i2s_base, TXFFR, 1); + else + i2s_write_reg(dev->i2s_base, RXFFR, 1); + + return 0; +} + static int dw_i2s_trigger(struct snd_pcm_substream *substream, int cmd, struct snd_soc_dai *dai) { @@ -294,6 +307,7 @@ static struct snd_soc_dai_ops dw_i2s_dai_ops = { .startup = dw_i2s_startup, .shutdown = dw_i2s_shutdown, .hw_params = dw_i2s_hw_params, + .prepare = dw_i2s_prepare, .trigger = dw_i2s_trigger, };