[PATCH AUTOSEL 6.12 15/26] ALSA: hda: cs35l41: Fix swapped l/r audio channels for Acer Helios laptops

[Sasha Levin <sashal@kernel.org>]

From: Stefan Binding <sbinding@opensource.cirrus.com>

[ Upstream commit e43a93c41982e82c1b703dd7fa9c1d965260fbb3 ]

Fixes audio channel assignment from ACPI using configuration table.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Link: https://patch.msgid.link/20250515162848.405055-3-sbinding@opensource.cirrus.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

**YES** This commit should be backported to stable kernel trees.
**Extensive Analysis:** **1. Nature of the Fix:** The commit fixes
swapped left/right audio channels for Acer Helios laptops by adding
three new entries to the `cs35l41_config_table[]`: - `{ "10251826", 2,
EXTERNAL, { CS35L41_LEFT, CS35L41_RIGHT, 0, 0 }, 0, -1, -1, 0, 0, 0 }` -
`{ "1025182C", 2, EXTERNAL, { CS35L41_LEFT, CS35L41_RIGHT, 0, 0 }, 0,
-1, -1, 0, 0, 0 }` - `{ "10251844", 2, EXTERNAL, { CS35L41_LEFT,
CS35L41_RIGHT, 0, 0 }, 0, -1, -1, 0, 0, 0 }` The corresponding model
table entries are also added to enable these configurations. **2.
Comparison with Historical Similar Commits:** This commit is **very
similar to Similar Commit #1 (Status: YES)** which also fixed swapped
l/r audio channels for Lenovo ThinkBook laptops. Both commits: - Fix the
same fundamental issue: swapped audio channels - Make identical types of
changes: correcting channel assignment in configuration tables - Are
small, contained fixes affecting only audio configuration data - Target
specific laptop models with broken audio channel mapping The primary
difference is that Similar Commit #1 modified existing entries by
swapping `CS35L41_LEFT` and `CS35L41_RIGHT`, while this commit adds new
entries with correct channel assignments. **3. Why This Qualifies for
Backporting:** **✅ Fixes Important User-Affecting Bug:** Swapped audio
channels are a significant usability issue that directly impacts users'
audio experience on affected Acer Helios laptops. **✅ Small and
Contained Change:** The fix only adds static configuration data - three
new entries in a lookup table. No algorithmic changes or complex logic
modifications. **✅ Minimal Risk of Regression:** Adding new entries to a
device-specific configuration table cannot break existing functionality
for other devices. The changes only affect the three specific Acer
laptop models. **✅ No Architectural Changes:** This is purely data-
driven configuration, not structural code changes. **✅ Specific Hardware
Support:** The SSID values (10251826, 1025182C, 10251844) are vendor-
specific identifiers for Acer devices (1025 = Acer vendor ID), ensuring
the fix only applies to the intended hardware. **4. Code Analysis
Verification:** From examining the current kernel tree at
`/home/sasha/linux/sound/pci/hda/cs35l41_hda_property.c`, I confirmed
that: - The file exists and contains the same structure as the commit -
No "1025" entries currently exist in the configuration table - The
pattern matches exactly with other vendor entries (HP: 103C, ASUS: 1043,
Lenovo: 17AA) **5. Risk Assessment:** - **Regression Risk: MINIMAL** -
Adding device-specific entries cannot affect other hardware - **Side
Effects: NONE** - Changes are isolated to specific Acer laptop models -
**Complexity: LOW** - Simple data table additions with no logic changes
**Conclusion:** This commit perfectly fits the stable tree criteria:
it's an important hardware-specific bug fix that affects users, with
minimal risk and no architectural changes. The historical precedent
(Similar Commit #1 with identical nature receiving YES status) strongly
supports backporting this fix.

 sound/pci/hda/cs35l41_hda_property.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sound/pci/hda/cs35l41_hda_property.c b/sound/pci/hda/cs35l41_hda_property.c
index 61d2314834e7b..d8249d997c2a0 100644
--- a/sound/pci/hda/cs35l41_hda_property.c
+++ b/sound/pci/hda/cs35l41_hda_property.c
@@ -31,6 +31,9 @@ struct cs35l41_config {
 };
 
 static const struct cs35l41_config cs35l41_config_table[] = {
+	{ "10251826", 2, EXTERNAL, { CS35L41_LEFT, CS35L41_RIGHT, 0, 0 }, 0, -1, -1, 0, 0, 0 },
+	{ "1025182C", 2, EXTERNAL, { CS35L41_LEFT, CS35L41_RIGHT, 0, 0 }, 0, -1, -1, 0, 0, 0 },
+	{ "10251844", 2, EXTERNAL, { CS35L41_LEFT, CS35L41_RIGHT, 0, 0 }, 0, -1, -1, 0, 0, 0 },
 	{ "10280B27", 2, INTERNAL, { CS35L41_LEFT, CS35L41_RIGHT, 0, 0 }, 1, 2, 0, 1000, 4500, 24 },
 	{ "10280B28", 2, INTERNAL, { CS35L41_LEFT, CS35L41_RIGHT, 0, 0 }, 1, 2, 0, 1000, 4500, 24 },
 	{ "10280BEB", 2, EXTERNAL, { CS35L41_LEFT, CS35L41_RIGHT, 0, 0 }, 1, -1, 0, 0, 0, 0 },
@@ -452,6 +455,9 @@ struct cs35l41_prop_model {
 static const struct cs35l41_prop_model cs35l41_prop_model_table[] = {
 	{ "CLSA0100", NULL, lenovo_legion_no_acpi },
 	{ "CLSA0101", NULL, lenovo_legion_no_acpi },
+	{ "CSC3551", "10251826", generic_dsd_config },
+	{ "CSC3551", "1025182C", generic_dsd_config },
+	{ "CSC3551", "10251844", generic_dsd_config },
 	{ "CSC3551", "10280B27", generic_dsd_config },
 	{ "CSC3551", "10280B28", generic_dsd_config },
 	{ "CSC3551", "10280BEB", generic_dsd_config },
-- 
2.39.5