From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrew Jackson , Mark Brown Subject: [PATCH 3.14 17/77] ASoC: dwc: Ensure FIFOs are flushed to prevent channel swap Date: Tue, 13 Jan 2015 23:22:57 -0800 Message-Id: <20150114072225.134706937@linuxfoundation.org> In-Reply-To: <20150114072224.182299947@linuxfoundation.org> References: <20150114072224.182299947@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Jackson commit 3475c3d034d7f276a474c8bd53f44b48c8bf669d upstream. 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 Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- sound/soc/dwc/designware_i2s.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- 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_p 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 .startup = dw_i2s_startup, .shutdown = dw_i2s_shutdown, .hw_params = dw_i2s_hw_params, + .prepare = dw_i2s_prepare, .trigger = dw_i2s_trigger, };