linux-kernel - Re: [PATCH 1/1] platform/x86/amd/pmf: Added a module parameter to disable the Smart PC function

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Message-ID: <a5f992bd-d4a0-4f01-b5a6-61f7b5dd5d46@amd.com>
Date: Mon, 19 Jan 2026 15:00:36 -0600
From: Mario Limonciello <mario.limonciello@....com>
To: Alexey Zagorodnikov <xglooom@...il.com>,
 platform-driver-x86@...r.kernel.org
Cc: Shyam Sundar S K <Shyam-sundar.S-k@....com>,
 Hans de Goede <hansg@...nel.org>,
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] platform/x86/amd/pmf: Added a module parameter to
 disable the Smart PC function



On 1/19/2026 2:20 PM, Alexey Zagorodnikov wrote:
> Addresses a low power limits issue on HP ZBook Ultra G1a
> https://gitlab.freedesktop.org/drm/amd/-/issues/4868
> 
> If vendor firmware capped APU power limits with 3rd-party AC adapters,
> the user can disable the Smart PC function via the module parameter
> 
> Signed-off-by: Alexey Zagorodnikov <xglooom@...il.com>

You should use a tag instead for "Link:".  It would look like this 
(assuming rest of commit text was OK):

Addresses a low power limits issue on HP ZBook Ultra G1a [1].
.
.
.
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/4868 [1]
Signed-off-by: Foo Bar <foo@....com>


> ---
>   drivers/platform/x86/amd/pmf/core.c | 19 ++++++++++++++-----
>   1 file changed, 14 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/platform/x86/amd/pmf/core.c b/drivers/platform/x86/amd/pmf/core.c
> index 8fc293c9c5380..00a4fc899c727 100644
> --- a/drivers/platform/x86/amd/pmf/core.c
> +++ b/drivers/platform/x86/amd/pmf/core.c
> @@ -53,6 +53,11 @@ static bool force_load;
>   module_param(force_load, bool, 0444);
>   MODULE_PARM_DESC(force_load, "Force load this driver on supported older platforms (experimental)");
>   
> +/* Force to disable Smart PC Solution */
> +static bool disable_smart_pc;
> +module_param(disable_smart_pc, bool, 0444);
> +MODULE_PARM_DESC(disable_smart_pc, "Disable Smart PC Solution");

Totally a nit/preference thing but I would think this is more logical:

static bool smart_pc = 1;
module_param(disable_smart_pc, bool, 0444);
MODULE_PARM_DESC(disable_smart_pc, "Smart PC Support");

Then the code reads the common flow more directly

if (smart_pc)
	//probe
else
	dev->smart_pc = false;

> +
>   static int amd_pmf_pwr_src_notify_call(struct notifier_block *nb, unsigned long event, void *data)
>   {
>   	struct amd_pmf_dev *pmf = container_of(nb, struct amd_pmf_dev, pwr_src_notifier);
> @@ -362,11 +367,15 @@ static void amd_pmf_init_features(struct amd_pmf_dev *dev)
>   		dev_dbg(dev->dev, "SPS enabled and Platform Profiles registered\n");
>   	}
>   
> -	amd_pmf_init_smart_pc(dev);
> -	if (dev->smart_pc_enabled) {
> -		dev_dbg(dev->dev, "Smart PC Solution Enabled\n");
> -		/* If Smart PC is enabled, no need to check for other features */
> -		return;
> +	if (disable_smart_pc) {
> +		dev->smart_pc_enabled = false;
> +	} else {
> +		amd_pmf_init_smart_pc(dev);
> +		if (dev->smart_pc_enabled) {
> +			dev_dbg(dev->dev, "Smart PC Solution Enabled\n");
> +			/* If Smart PC is enabled, no need to check for other features */
> +			return;
> +		}
>   	}
>   
>   	if (is_apmf_func_supported(dev, APMF_FUNC_AUTO_MODE)) {