diff mbox series

[02/11] cpufreq: amd-pstate: show CPPC debug message if CPPC is not supported

Message ID 4b4a1a6b30a2dc6c95e550c62b230bc3788af415.1715065568.git.perry.yuan@amd.com
State Superseded
Headers show
Series AMD Pstate Driver Fixes and Improvements | expand

Commit Message

Yuan, Perry May 7, 2024, 7:15 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 showed 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.

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

Mario Limonciello May 7, 2024, 2:45 p.m. UTC | #1
On 5/7/2024 02:15, 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 showed if CPPC is not supported.

shown

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

You should add a "Reported-by:" here for Paul too.

> 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(+)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index be7f2d3c86b6..cb766c061c86 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1687,6 +1687,20 @@ 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;
> @@ -1695,6 +1709,11 @@ 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;
diff mbox series

Patch

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index be7f2d3c86b6..cb766c061c86 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1687,6 +1687,20 @@  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;
@@ -1695,6 +1709,11 @@  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;