From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lukasz Majewski Subject: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Date: Sun, 3 Sep 2017 13:05:01 +0200 Message-ID: <1504436701-20700-1-git-send-email-lukma@denx.de> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Timur Tabi , Nicolin Chen , Xiubo Li , Fabio Estevam , Liam Girdwood , Mark Brown , Jaroslav Kysela , Takashi Iwai Cc: alsa-devel@alsa-project.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Lukasz Majewski List-Id: alsa-devel@alsa-project.org The problem is visible in the following setup (on the imx6q): "simple-audio-card" -> ssi2 -> I2S + I2C -> codec The function call log (simple-card probe -> CONFIG_SND_SIMPLE_CARD): asoc_simple_card_init_dai() @ sound/soc/generic/simple-card-utils.c snd_soc_dai_set_sysclk() fsl_ssi_set_dai_sysclk() @ sound/soc/fsl/fsl_ssi.c The last call is changing the bit clock (BCLK) frequency to SSI's IP block clock (ipg = 66 MHz) [1]. This is wrong, since IMX SSI block requires the I2S BCLK to be less than 1/5 of [1]. As a result the driver initialization passes without any errors, but the speaker-test test case breaks. This commit checks if the fsl_ssi_set_dai_sysclk() frequency passed is not equal to [1]. Signed-off-by: Lukasz Majewski --- sound/soc/fsl/fsl_ssi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c index 173cb84..1186fa9 100644 --- a/sound/soc/fsl/fsl_ssi.c +++ b/sound/soc/fsl/fsl_ssi.c @@ -809,6 +809,8 @@ static int fsl_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai, int clk_id, unsigned int freq, int dir) { struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai); + if (clk_get_rate(ssi_private->clk) == freq) + return 0; ssi_private->bitclk_freq = freq; -- 2.1.4