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From:   Richard Fitzgerald <rf@opensource.cirrus.com>
To:     <tiwai@suse.com>
CC:     <alsa-devel@alsa-project.org>, <patches@opensource.cirrus.com>,
        <linux-kernel@vger.kernel.org>,
        Richard Fitzgerald <rf@opensource.cirrus.com>
Subject: [PATCH v2] ALSA: hda: cs35l56: Fix missing RESET GPIO if _SUB is missing
Date:   Thu, 14 Sep 2023 16:25:25 +0100
Message-ID: <20230914152525.20829-1-rf@opensource.cirrus.com>
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Precedence: bulk

In cs35l56_hda_read_acpi() do not return if ACPI _SUB is missing.

A missing _SUB means that the driver cannot load a system-specific
firmware, because the firmware is identified by the _SUB. But it can
fallback to a generic firmware. Unfortunately this was being handled
by immediately returning 0, which would skip the remaining ACPI
configuration in cs35l56_hda_read_acpi() and so it would not get the
RESET GPIO.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: 73cfbfa9caea ("ALSA: hda/cs35l56: Add driver for Cirrus Logic CS35L56 amplifier")
---
 sound/pci/hda/cs35l56_hda.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/sound/pci/hda/cs35l56_hda.c b/sound/pci/hda/cs35l56_hda.c
index bc75865b5de8..87ffe8fbff99 100644
--- a/sound/pci/hda/cs35l56_hda.c
+++ b/sound/pci/hda/cs35l56_hda.c
@@ -865,15 +865,13 @@ static int cs35l56_hda_read_acpi(struct cs35l56_hda *cs35l56, int id)
 	sub = acpi_get_subsystem_id(ACPI_HANDLE(cs35l56->base.dev));
 
 	if (IS_ERR(sub)) {
-		/* If no ACPI SUB, return 0 and fallback to legacy firmware path, otherwise fail */
-		if (PTR_ERR(sub) == -ENODATA)
-			return 0;
-		else
-			return PTR_ERR(sub);
+		dev_info(cs35l56->base.dev,
+			 "Read ACPI _SUB failed(%ld): fallback to generic firmware\n",
+			 PTR_ERR(sub));
+	} else {
+		cs35l56->system_name = sub;
 	}
 
-	cs35l56->system_name = sub;
-
 	cs35l56->base.reset_gpio = devm_gpiod_get_index_optional(cs35l56->base.dev,
 								 "reset",
 								 cs35l56->index,
-- 
2.30.2