diff mbox series

[v2,03/10] cpufreq: amd-pstate: show CPPC debug message if CPPC is not supported

Message ID e6132ee6b6e3c3db5cd9c1e8adc0777881bd2cbd.1715356532.git.perry.yuan@amd.com
State Superseded
Headers show
Series AMD Pstate Driver Fixes and Improvements | expand

Commit Message

Yuan, Perry May 13, 2024, 2:07 a.m. UTC
Add CPU ID checking in case the driver attempt to load on systems where
CPPC functionality is unavailable. And the warning message will not
be shown if CPPC is not supported.

It will also print debug message if the CPU has no CPPC support that
helps to debug the driver loading failure issue.

Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Closes: https://lore.kernel.org/linux-pm/CYYPR12MB8655D32EA18574C9497E888A9C122@CYYPR12MB8655.namprd12.prod.outlook.com/T/#t
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

Comments

Gautham R. Shenoy June 6, 2024, 2:26 p.m. UTC | #1
On Mon, May 13, 2024 at 10:07:21AM +0800, Perry Yuan wrote:
> Add CPU ID checking in case the driver attempt to load on systems where
> CPPC functionality is unavailable. And the warning message will not
> be shown if CPPC is not supported.
> 
> It will also print debug message if the CPU has no CPPC support that
> helps to debug the driver loading failure issue.
> 
> Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
> Closes: https://lore.kernel.org/linux-pm/CYYPR12MB8655D32EA18574C9497E888A9C122@CYYPR12MB8655.namprd12.prod.outlook.com/T/#t
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

> ---
>  drivers/cpufreq/amd-pstate.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 9ca22e94f3f3..3109b46fb02e 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1701,6 +1701,20 @@ static int __init amd_pstate_set_driver(int mode_idx)
>  	return -EINVAL;
>  }
>  
> +/**
> + * CPPC function is not supported for family ID 17H with model_ID ranging from 0x10 to 0x2F.
> + * show the debug message that helps to check if the CPU has CPPC support for loading issue.
> + */
> +static bool amd_cppc_supported(void)
> +{
> +	if ((boot_cpu_data.x86 == 0x17) && (boot_cpu_data.x86_model < 0x30)) {
> +		pr_debug_once("CPPC feature is not supported by the processor\n");
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
>  static int __init amd_pstate_init(void)
>  {
>  	struct device *dev_root;
> @@ -1709,6 +1723,11 @@ static int __init amd_pstate_init(void)
>  	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
>  		return -ENODEV;
>  
> +	/* show debug message only if CPPC is not supported */
> +	if (!amd_cppc_supported())
> +		return -EOPNOTSUPP;
> +
> +	/* show warning message when BIOS broken or ACPI disabled */
>  	if (!acpi_cpc_valid()) {
>  		pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n");
>  		return -ENODEV;
> -- 
> 2.34.1
>
diff mbox series

Patch

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 9ca22e94f3f3..3109b46fb02e 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1701,6 +1701,20 @@  static int __init amd_pstate_set_driver(int mode_idx)
 	return -EINVAL;
 }
 
+/**
+ * CPPC function is not supported for family ID 17H with model_ID ranging from 0x10 to 0x2F.
+ * show the debug message that helps to check if the CPU has CPPC support for loading issue.
+ */
+static bool amd_cppc_supported(void)
+{
+	if ((boot_cpu_data.x86 == 0x17) && (boot_cpu_data.x86_model < 0x30)) {
+		pr_debug_once("CPPC feature is not supported by the processor\n");
+		return false;
+	}
+
+	return true;
+}
+
 static int __init amd_pstate_init(void)
 {
 	struct device *dev_root;
@@ -1709,6 +1723,11 @@  static int __init amd_pstate_init(void)
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
 		return -ENODEV;
 
+	/* show debug message only if CPPC is not supported */
+	if (!amd_cppc_supported())
+		return -EOPNOTSUPP;
+
+	/* show warning message when BIOS broken or ACPI disabled */
 	if (!acpi_cpc_valid()) {
 		pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n");
 		return -ENODEV;