From f082bb59b72039a2326ec1a44496899fb8aa6d0e Mon Sep 17 00:00:00 2001
From: Sylwester Nawrocki <s.nawrocki@samsung.com>
Date: Fri, 31 Jul 2020 19:38:34 +0200
Subject: [PATCH] ASoC: wm8994: Avoid attempts to read unreadable registers
Git-commit: f082bb59b72039a2326ec1a44496899fb8aa6d0e
Patch-mainline: v5.9-rc2
References: jsc#SLE-16518

The driver supports WM1811, WM8994, WM8958 devices but according to
documentation and the regmap definitions the WM8958_DSP2_* registers
are only available on WM8958. In current code these registers are
being accessed as if they were available on all the three chips.

When starting playback on WM1811 CODEC multiple errors like:
"wm8994-codec wm8994-codec: ASoC: error at soc_component_read_no_lock on wm8994-codec: -5"
can be seen, which is caused by attempts to read an unavailable
WM8958_DSP2_PROGRAM register. The issue has been uncovered by recent
commit "e2329ee ASoC: soc-component: add soc_component_err()".

This patch adds a check in wm8958_aif_ev() callback so the DSP2 handling
is only done for WM8958.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200731173834.23832-1-s.nawrocki@samsung.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 sound/soc/codecs/wm8958-dsp2.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sound/soc/codecs/wm8958-dsp2.c b/sound/soc/codecs/wm8958-dsp2.c
index 68a3b48e6b31..3bce9a14f0f3 100644
--- a/sound/soc/codecs/wm8958-dsp2.c
+++ b/sound/soc/codecs/wm8958-dsp2.c
@@ -412,8 +412,12 @@ int wm8958_aif_ev(struct snd_soc_dapm_widget *w,
 		  struct snd_kcontrol *kcontrol, int event)
 {
 	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
+	struct wm8994 *control = dev_get_drvdata(component->dev->parent);
 	int i;
 
+	if (control->type != WM8958)
+		return 0;
+
 	switch (event) {
 	case SND_SOC_DAPM_POST_PMU:
 	case SND_SOC_DAPM_PRE_PMU:
-- 
2.16.4