1 files changed, 46 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0192-rpi-wm8804-soundcard-configure-wm8804-clocks-only-on.patch b/target/linux/brcm2708/patches-4.19/950-0192-rpi-wm8804-soundcard-configure-wm8804-clocks-only-on.patch
new file mode 100644
index 0000000000..7edd25f9eb
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.19/950-0192-rpi-wm8804-soundcard-configure-wm8804-clocks-only-on.patch
@@ -0,0 +1,46 @@
+From f6b133a056e8fde7f4707e2874e204c7d5d671a2 Mon Sep 17 00:00:00 2001
+From: Matthias Reichl <hias@horus.com>
+Date: Sun, 18 Nov 2018 15:32:28 +0100
+Subject: [PATCH] rpi-wm8804-soundcard: configure wm8804 clocks only on
+ rate change
+
+This should avoid clicks when stopping and immediately afterwards
+starting a stream with the same samplerate as before.
+
+Signed-off-by: Matthias Reichl <hias@horus.com>
+---
+ sound/soc/bcm/rpi-wm8804-soundcard.c | 9 +++++++++
+ 1 file changed, 9 insertions(+)
+
+--- a/sound/soc/bcm/rpi-wm8804-soundcard.c
++++ b/sound/soc/bcm/rpi-wm8804-soundcard.c
+@@ -64,6 +64,7 @@ struct snd_rpi_wm8804_drvdata {
+ 
+ static struct gpio_desc *snd_clk44gpio;
+ static struct gpio_desc *snd_clk48gpio;
++static int wm8804_samplerate = 0;
+ 
+ #define CLK_44EN_RATE 22579200UL
+ #define CLK_48EN_RATE 24576000UL
+@@ -117,6 +118,12 @@ static int snd_rpi_wm8804_hw_params(stru
+ 	struct wm8804_clk_cfg clk_cfg;
+ 	int samplerate = params_rate(params);
+ 
++	if (samplerate == wm8804_samplerate)
++		return 0;
++
++	/* clear until all clocks are setup properly */
++	wm8804_samplerate = 0;
++
+ 	snd_rpi_wm8804_clk_cfg(samplerate, &clk_cfg);
+ 
+ 	pr_debug("%s samplerate: %d mclk_freq: %u mclk_div: %u sysclk: %u\n",
+@@ -163,6 +170,8 @@ static int snd_rpi_wm8804_hw_params(stru
+ 		return ret;
+ 	}
+ 
++	wm8804_samplerate = samplerate;
++
+ 	/* set sampling frequency status bits */
+ 	snd_soc_component_update_bits(component, WM8804_SPDTX4, 0x0f,
+ 			sampling_freq);