[PATCH 5/8] firmware: cs_dsp: Clear core reset for cache

From: Charles Keepax <ckeepax@opensource.cirrus.com>
To: <broonie@kernel.org>
Cc: patches@opensource.cirrus.com, alsa-devel@alsa-project.org,
	david.rhodes@cirrus.com, lgirdwood@gmail.com, tiwai@suse.com
Subject: [PATCH 5/8] firmware: cs_dsp: Clear core reset for cache
Date: Wed, 5 Jan 2022 11:30:23 +0000	[thread overview]
Message-ID: <20220105113026.18955-6-ckeepax@opensource.cirrus.com> (raw)
In-Reply-To: <20220105113026.18955-1-ckeepax@opensource.cirrus.com>

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>
---
 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 5af8171d6cedf..e48108e694f8d 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)
-- 
2.11.0

