[5/6] cppc_acpi: print error message if CPPC is unsupported

Message ID a6c3790105fa30e89f39f0dccc7d699f5c1c30b7.1706690577.git.perry.yuan@amd.com
State New
Headers
Series AMD Pstate Fixes And Enhancements |

Commit Message

Yuan, Perry Jan. 31, 2024, 8:50 a.m. UTC
  to be more clear what is wrong with CPPC when pstate driver failed to
load which has dependency on the CPPC capabilities.

Add one more debug message to notify user if CPPC is not supported by
the CPU, then it will be easy to find out what need to fix for pstate
driver loading issue.

[    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled

Above message is not clear enough to verify whether CPPC is not supported.

Signed-off-by: Perry Yuan <perry.yuan@amd.com>
---
 drivers/acpi/cppc_acpi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
  

Comments

Mario Limonciello Jan. 31, 2024, 9:51 p.m. UTC | #1
On 1/31/2024 02:50, Perry Yuan wrote:
> to be more clear what is wrong with CPPC when pstate driver failed to
> load which has dependency on the CPPC capabilities.
> 
> Add one more debug message to notify user if CPPC is not supported by
> the CPU, then it will be easy to find out what need to fix for pstate
> driver loading issue.
> 
> [    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled
> 
> Above message is not clear enough to verify whether CPPC is not supported.
> 
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
> ---
>   drivers/acpi/cppc_acpi.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 7ff269a78c20..217c11c12b57 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -676,8 +676,10 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
>   
>   	if (!osc_sb_cppc2_support_acked) {
>   		pr_debug("CPPC v2 _OSC not acked\n");
> -		if (!cpc_supported_by_cpu())
> -			return -ENODEV;
> +		if (!cpc_supported_by_cpu()) {
> +				pr_debug("CPPC is not supported\n");

I would argue this doesn't add any value to a user.  To help a user it 
should be "CPPC is not supported by the CPU".

> +				return -ENODEV;
> +			}

This whitespace is wrong

>   	}
>   
>   	/* Parse the ACPI _CPC table for this CPU. */
  

Patch

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 7ff269a78c20..217c11c12b57 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -676,8 +676,10 @@  int acpi_cppc_processor_probe(struct acpi_processor *pr)
 
 	if (!osc_sb_cppc2_support_acked) {
 		pr_debug("CPPC v2 _OSC not acked\n");
-		if (!cpc_supported_by_cpu())
-			return -ENODEV;
+		if (!cpc_supported_by_cpu()) {
+				pr_debug("CPPC is not supported\n");
+				return -ENODEV;
+			}
 	}
 
 	/* Parse the ACPI _CPC table for this CPU. */