[PATCH] platform/x86: asus-wmi: Fix driver not binding when fan curve control probe fails

[PATCH] platform/x86: asus-wmi: Fix driver not binding when fan curve control probe fails

[Hans de Goede]

Before this commit fan_curve_check_present() was trying to not cause
the probe to fail on devices without fan curve control by testing for
known error codes returned by asus_wmi_evaluate_method_buf().

Checking for ENODATA or ENODEV, with the latter being returned by this
function when an ACPI integer with a value of ASUS_WMI_UNSUPPORTED_METHOD
is returned. But for other ACPI integer returns this function just returns
them as is, including the ASUS_WMI_DSTS_UNKNOWN_BIT value of 2.

On the Asus U36SD ASUS_WMI_DSTS_UNKNOWN_BIT gets returned, leading to:

  asus-nb-wmi: probe of asus-nb-wmi failed with error 2

Instead of playing whack a mole with error codes here, simply treat all
errors as there not being any fan curves, fixing the driver no longer
loading on the Asus U36SD laptop.

Fixes: e3d13da7f77d ("platform/x86: asus-wmi: Fix regression when probing for fan curve control")
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2079125
Cc: Luke D. Jones <luke@ljones.dev>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/platform/x86/asus-wmi.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 2104a2621e50..20efcf82ce8d 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -2223,9 +2223,10 @@ static int fan_curve_check_present(struct asus_wmi *asus, bool *available,
 
 	err = fan_curve_get_factory_default(asus, fan_dev);
 	if (err) {
-		if (err == -ENODEV || err == -ENODATA)
-			return 0;
-		return err;
+		pr_debug("fan_curve_get_factory_default(0x%08x) failed: %d\n",
+			 fan_dev, err);
+		/* Don't cause probe to fail on devices without fan-curves */
+		return 0;
 	}
 
 	*available = true;
-- 
2.36.0

Re: [PATCH] platform/x86: asus-wmi: Fix driver not binding when fan curve control probe fails

[Hans de Goede]

Hi,

On 4/27/22 13:49, Hans de Goede wrote:
> Before this commit fan_curve_check_present() was trying to not cause
> the probe to fail on devices without fan curve control by testing for
> known error codes returned by asus_wmi_evaluate_method_buf().
> 
> Checking for ENODATA or ENODEV, with the latter being returned by this
> function when an ACPI integer with a value of ASUS_WMI_UNSUPPORTED_METHOD
> is returned. But for other ACPI integer returns this function just returns
> them as is, including the ASUS_WMI_DSTS_UNKNOWN_BIT value of 2.
> 
> On the Asus U36SD ASUS_WMI_DSTS_UNKNOWN_BIT gets returned, leading to:
> 
>   asus-nb-wmi: probe of asus-nb-wmi failed with error 2
> 
> Instead of playing whack a mole with error codes here, simply treat all
> errors as there not being any fan curves, fixing the driver no longer
> loading on the Asus U36SD laptop.
> 
> Fixes: e3d13da7f77d ("platform/x86: asus-wmi: Fix regression when probing for fan curve control")
> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2079125
> Cc: Luke D. Jones <luke@ljones.dev>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

I've added this to my review-hans (soon to be for-next) branch now.

Regards,

Hans



> ---
>  drivers/platform/x86/asus-wmi.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 2104a2621e50..20efcf82ce8d 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -2223,9 +2223,10 @@ static int fan_curve_check_present(struct asus_wmi *asus, bool *available,
>  
>  	err = fan_curve_get_factory_default(asus, fan_dev);
>  	if (err) {
> -		if (err == -ENODEV || err == -ENODATA)
> -			return 0;
> -		return err;
> +		pr_debug("fan_curve_get_factory_default(0x%08x) failed: %d\n",
> +			 fan_dev, err);
> +		/* Don't cause probe to fail on devices without fan-curves */
> +		return 0;
>  	}
>  
>  	*available = true;