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* [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq
@ 2017-09-03 11:05 Lukasz Majewski
  2017-09-03 12:44   ` Fabio Estevam
  2017-09-05  5:06 ` Nicolin Chen
  0 siblings, 2 replies; 45+ messages in thread
From: Lukasz Majewski @ 2017-09-03 11:05 UTC (permalink / raw)
  To: Timur Tabi, Nicolin Chen, Xiubo Li, Fabio Estevam, Liam Girdwood,
	Mark Brown, Jaroslav Kysela, Takashi Iwai
  Cc: alsa-devel, linuxppc-dev, linux-kernel, Lukasz Majewski

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 <lukma@denx.de>
---
 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

^ permalink raw reply related	[flat|nested] 45+ messages in thread

end of thread, other threads:[~2017-09-08  0:38 UTC | newest]

Thread overview: 45+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-09-03 11:05 [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Lukasz Majewski
2017-09-03 12:44 ` Fabio Estevam
2017-09-03 12:44   ` Fabio Estevam
2017-09-03 14:40   ` Łukasz Majewski
2017-09-03 15:29     ` Fabio Estevam
2017-09-03 15:29       ` Fabio Estevam
2017-09-03 15:29       ` Fabio Estevam
2017-09-05  5:20     ` Nicolin Chen
2017-09-05  8:35       ` Łukasz Majewski
2017-09-05 18:11         ` Nicolin Chen
2017-09-05 21:13           ` Łukasz Majewski
2017-09-05 21:13             ` Łukasz Majewski
2017-09-05 22:52             ` Nicolin Chen
2017-09-05 22:52               ` Nicolin Chen
2017-09-06  9:22               ` Łukasz Majewski
2017-09-06  9:22                 ` Łukasz Majewski
2017-09-06 17:33                 ` Nicolin Chen
2017-09-06 17:33                   ` Nicolin Chen
2017-09-06 18:35                   ` Łukasz Majewski
2017-09-06 19:47                     ` Nicolin Chen
2017-09-06 19:47                       ` Nicolin Chen
2017-09-06 21:18                       ` Łukasz Majewski
2017-09-06 21:18                         ` Łukasz Majewski
2017-09-07 23:10                       ` Łukasz Majewski
2017-09-07 23:10                         ` Łukasz Majewski
2017-09-08  0:39                         ` Nicolin Chen
2017-09-08  0:39                           ` Nicolin Chen
2017-09-05 23:20             ` Fabio Estevam
2017-09-05 23:20               ` Fabio Estevam
2017-09-05 23:20               ` Fabio Estevam
2017-09-06  8:44               ` Łukasz Majewski
2017-09-05 20:14         ` Fabio Estevam
2017-09-05 20:14           ` Fabio Estevam
2017-09-05 21:14           ` Łukasz Majewski
2017-09-05  5:06 ` Nicolin Chen
2017-09-05  7:37   ` Łukasz Majewski
2017-09-05  7:52     ` Nicolin Chen
2017-09-05  8:19       ` Łukasz Majewski
2017-09-05  8:19         ` Łukasz Majewski
2017-09-05 15:15         ` Mark Brown
2017-09-05 15:15           ` Mark Brown
2017-09-05 17:45           ` Nicolin Chen
2017-09-07 13:44             ` Mark Brown
2017-09-07 13:44               ` Mark Brown
2017-09-07 23:03               ` Nicolin Chen

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