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From:   Stefan Binding <sbinding@opensource.cirrus.com>
To:     Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>
CC:     <alsa-devel@alsa-project.org>, <linux-kernel@vger.kernel.org>,
        <patches@opensource.cirrus.com>,
        Stefan Binding <sbinding@opensource.cirrus.com>
Subject: [PATCH v2 1/3] ALSA: hda: cs35l41: Clean up Firmware Load Controls
Date:   Mon, 5 Jun 2023 16:28:53 +0100
Message-ID: <20230605152855.448115-2-sbinding@opensource.cirrus.com>
In-Reply-To: <20230605152855.448115-1-sbinding@opensource.cirrus.com>
References: <20230605152855.448115-1-sbinding@opensource.cirrus.com>
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Ensure Firmware Load control and Firmware Type control
returns 1 when the value changes.

Remove fw_mutex from firmware load control put, since it is
unnecessary, and prevents any possibility of mutex inversion.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
---
 sound/pci/hda/cs35l41_hda.c | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/sound/pci/hda/cs35l41_hda.c b/sound/pci/hda/cs35l41_hda.c
index b5210abb5141f..d100189e15b83 100644
--- a/sound/pci/hda/cs35l41_hda.c
+++ b/sound/pci/hda/cs35l41_hda.c
@@ -835,34 +835,26 @@ static int cs35l41_fw_load_ctl_put(struct snd_kcontrol *kcontrol,
 				   struct snd_ctl_elem_value *ucontrol)
 {
 	struct cs35l41_hda *cs35l41 = snd_kcontrol_chip(kcontrol);
-	unsigned int ret = 0;
-
-	mutex_lock(&cs35l41->fw_mutex);
 
 	if (cs35l41->request_fw_load == ucontrol->value.integer.value[0])
-		goto err;
+		return 0;
 
 	if (cs35l41->fw_request_ongoing) {
 		dev_dbg(cs35l41->dev, "Existing request not complete\n");
-		ret = -EBUSY;
-		goto err;
+		return -EBUSY;
 	}
 
 	/* Check if playback is ongoing when initial request is made */
 	if (cs35l41->playback_started) {
 		dev_err(cs35l41->dev, "Cannot Load/Unload firmware during Playback\n");
-		ret = -EBUSY;
-		goto err;
+		return -EBUSY;
 	}
 
 	cs35l41->fw_request_ongoing = true;
 	cs35l41->request_fw_load = ucontrol->value.integer.value[0];
 	schedule_work(&cs35l41->fw_load_work);
 
-err:
-	mutex_unlock(&cs35l41->fw_mutex);
-
-	return ret;
+	return 1;
 }
 
 static int cs35l41_fw_type_ctl_get(struct snd_kcontrol *kcontrol,
@@ -881,8 +873,12 @@ static int cs35l41_fw_type_ctl_put(struct snd_kcontrol *kcontrol,
 	struct cs35l41_hda *cs35l41 = snd_kcontrol_chip(kcontrol);
 
 	if (ucontrol->value.enumerated.item[0] < HDA_CS_DSP_NUM_FW) {
-		cs35l41->firmware_type = ucontrol->value.enumerated.item[0];
-		return 0;
+		if (cs35l41->firmware_type != ucontrol->value.enumerated.item[0]) {
+			cs35l41->firmware_type = ucontrol->value.enumerated.item[0];
+			return 1;
+		} else {
+			return 0;
+		}
 	}
 
 	return -EINVAL;
-- 
2.34.1