[PATCH] ALSA: hda: cs35l56: Fix missing RESET GPIO if _SUB is missing

[PATCH] ALSA: hda: cs35l56: Fix missing RESET GPIO if _SUB is missing

[Richard Fitzgerald]

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 | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/sound/pci/hda/cs35l56_hda.c b/sound/pci/hda/cs35l56_hda.c
index 9e4976bdb5e0..a9844336bdc9 100644
--- a/sound/pci/hda/cs35l56_hda.c
+++ b/sound/pci/hda/cs35l56_hda.c
@@ -864,15 +864,11 @@ 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);
-	}
-
-	cs35l56->system_name = sub;
+	if (IS_ERR(sub))
+		dev_err_probe(cs35l56->base.dev, PTR_ERR(sub),
+			      "Read ACPI _SUB failed: fallback to generic firmware\n");
+	else
+		cs35l56->system_name = sub;
 
 	cs35l56->base.reset_gpio = devm_gpiod_get_index_optional(cs35l56->base.dev,
 								 "reset",
-- 
2.30.2

Re: [PATCH] ALSA: hda: cs35l56: Fix missing RESET GPIO if _SUB is missing

[Takashi Iwai]

On Thu, 14 Sep 2023 14:11:20 +0200,
Richard Fitzgerald wrote:
> 
> 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 | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/sound/pci/hda/cs35l56_hda.c b/sound/pci/hda/cs35l56_hda.c
> index 9e4976bdb5e0..a9844336bdc9 100644
> --- a/sound/pci/hda/cs35l56_hda.c
> +++ b/sound/pci/hda/cs35l56_hda.c
> @@ -864,15 +864,11 @@ 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);
> -	}
> -
> -	cs35l56->system_name = sub;
> +	if (IS_ERR(sub))
> +		dev_err_probe(cs35l56->base.dev, PTR_ERR(sub),
> +			      "Read ACPI _SUB failed: fallback to generic firmware\n");

Do we want to show as an error?  Since the driver continue to work, it
could be rather dev_info()?


thanks,

Takashi