Patch "ASoC: wm8960: Fix clock configuration on slave mode" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ASoC: wm8960: Fix clock configuration on slave mode

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     asoc-wm8960-fix-clock-configuration-on-slave-mode.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 5ac72cae50025b6bb40d6594b4f66d37d4b43516
Author: Shengjiu Wang <shengjiu.wang@xxxxxxx>
Date:   Wed Oct 13 13:17:04 2021 +0800

    ASoC: wm8960: Fix clock configuration on slave mode
    
    [ Upstream commit 6b9b546dc00797c74bef491668ce5431ff54e1e2 ]
    
    There is a noise issue for 8kHz sample rate on slave mode.
    Compared with master mode, the difference is the DACDIV
    setting, after correcting the DACDIV, the noise is gone.
    
    There is no noise issue for 48kHz sample rate, because
    the default value of DACDIV is correct for 48kHz.
    
    So wm8960_configure_clocking() should be functional for
    ADC and DAC function even if it is slave mode.
    
    In order to be compatible for old use case, just add
    condition for checking that sysclk is zero with
    slave mode.
    
    Fixes: 0e50b51aa22f ("ASoC: wm8960: Let wm8960 driver configure its bit clock and frame clock")
    Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
    Acked-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/1634102224-3922-1-git-send-email-shengjiu.wang@xxxxxxx
    Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 88e869d16714..abd5c12764f0 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -755,9 +755,16 @@ static int wm8960_configure_clocking(struct snd_soc_component *component)
 	int i, j, k;
 	int ret;
 
-	if (!(iface1 & (1<<6))) {
-		dev_dbg(component->dev,
-			"Codec is slave mode, no need to configure clock\n");
+	/*
+	 * For Slave mode clocking should still be configured,
+	 * so this if statement should be removed, but some platform
+	 * may not work if the sysclk is not configured, to avoid such
+	 * compatible issue, just add '!wm8960->sysclk' condition in
+	 * this if statement.
+	 */
+	if (!(iface1 & (1 << 6)) && !wm8960->sysclk) {
+		dev_warn(component->dev,
+			 "slave mode, but proceeding with no clock configuration\n");
 		return 0;
 	}