From 7aa1cc1091e0a424e9e7711ca381ebe98b6865bc Mon Sep 17 00:00:00 2001
From: Charles Keepax <ckeepax@opensource.cirrus.com>
Date: Wed, 5 Jan 2022 11:30:23 +0000
Subject: [PATCH] firmware: cs_dsp: Clear core reset for cache
Git-commit: 7aa1cc1091e0a424e9e7711ca381ebe98b6865bc
Patch-mainline: v5.17-rc1
References: bsc#1203699

If the Halo registers are kept in the register cache the
HALO_CORE_RESET bit will be retained as 1 after reset is triggered in
cs_dsp_halo_start_core. This will cause subsequent writes to reset
the core which is not desired. Apart from this bit the rest of the
register bits are cacheable, so for safety sake clear the bit to
ensure the cache is consistent.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220105113026.18955-6-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/firmware/cirrus/cs_dsp.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c
index 5af8171d6ced..e48108e694f8 100644
--- a/drivers/firmware/cirrus/cs_dsp.c
+++ b/drivers/firmware/cirrus/cs_dsp.c
@@ -2744,10 +2744,16 @@ EXPORT_SYMBOL_GPL(cs_dsp_stop);
 
 static int cs_dsp_halo_start_core(struct cs_dsp *dsp)
 {
-	return regmap_update_bits(dsp->regmap,
-				  dsp->base + HALO_CCM_CORE_CONTROL,
-				  HALO_CORE_RESET | HALO_CORE_EN,
-				  HALO_CORE_RESET | HALO_CORE_EN);
+	int ret;
+
+	ret = regmap_update_bits(dsp->regmap, dsp->base + HALO_CCM_CORE_CONTROL,
+				 HALO_CORE_RESET | HALO_CORE_EN,
+				 HALO_CORE_RESET | HALO_CORE_EN);
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(dsp->regmap, dsp->base + HALO_CCM_CORE_CONTROL,
+				  HALO_CORE_RESET, 0);
 }
 
 static void cs_dsp_halo_stop_core(struct cs_dsp *dsp)
-- 
2.35.3