[PATCH v2] platform/x86/dell: Set USTT mode according to BIOS after reboot

[PATCH v2] platform/x86/dell: Set USTT mode according to BIOS after reboot

[Shyam Sundar S K]

After a reboot, if the user changes the thermal setting in the BIOS, the
BIOS applies this change. However, the current `dell-pc` driver does not
recognize the updated USTT value, resulting in inconsistent thermal
profiles between Windows and Linux.

To ensure alignment with Windows behavior, read the current USTT settings
during driver initialization and update the dell-pc USTT profile
accordingly whenever a change is detected.

Cc: Yijun Shen <Yijun.Shen@Dell.com>
Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
---
 drivers/platform/x86/dell/dell-pc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/platform/x86/dell/dell-pc.c b/drivers/platform/x86/dell/dell-pc.c
index 48cc7511905a..becdd9aaef29 100644
--- a/drivers/platform/x86/dell/dell-pc.c
+++ b/drivers/platform/x86/dell/dell-pc.c
@@ -228,6 +228,8 @@ static int thermal_platform_profile_get(struct device *dev,
 
 static int thermal_platform_profile_probe(void *drvdata, unsigned long *choices)
 {
+	int current_mode;
+
 	if (supported_modes & DELL_QUIET)
 		__set_bit(PLATFORM_PROFILE_QUIET, choices);
 	if (supported_modes & DELL_COOL_BOTTOM)
@@ -237,6 +239,13 @@ static int thermal_platform_profile_probe(void *drvdata, unsigned long *choices)
 	if (supported_modes & DELL_PERFORMANCE)
 		__set_bit(PLATFORM_PROFILE_PERFORMANCE, choices);
 
+	/* Make sure that ACPI is in sync with the profile set by USTT */
+	current_mode = thermal_get_mode();
+	if (current_mode < 0)
+		return current_mode;
+
+	thermal_set_mode(current_mode);
+
 	return 0;
 }
 
-- 
2.34.1

Re: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS after reboot

[Mario Limonciello]

On 9/16/25 6:51 AM, Shyam Sundar S K wrote:
> After a reboot, if the user changes the thermal setting in the BIOS, the
> BIOS applies this change. However, the current `dell-pc` driver does not
> recognize the updated USTT value, resulting in inconsistent thermal
> profiles between Windows and Linux.
> 
> To ensure alignment with Windows behavior, read the current USTT settings
> during driver initialization and update the dell-pc USTT profile
> accordingly whenever a change is detected.
> 
> Cc: Yijun Shen <Yijun.Shen@Dell.com>
> Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
> Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>> ---
>   drivers/platform/x86/dell/dell-pc.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/platform/x86/dell/dell-pc.c b/drivers/platform/x86/dell/dell-pc.c
> index 48cc7511905a..becdd9aaef29 100644
> --- a/drivers/platform/x86/dell/dell-pc.c
> +++ b/drivers/platform/x86/dell/dell-pc.c
> @@ -228,6 +228,8 @@ static int thermal_platform_profile_get(struct device *dev,
>   
>   static int thermal_platform_profile_probe(void *drvdata, unsigned long *choices)
>   {
> +	int current_mode;
> +
>   	if (supported_modes & DELL_QUIET)
>   		__set_bit(PLATFORM_PROFILE_QUIET, choices);
>   	if (supported_modes & DELL_COOL_BOTTOM)
> @@ -237,6 +239,13 @@ static int thermal_platform_profile_probe(void *drvdata, unsigned long *choices)
>   	if (supported_modes & DELL_PERFORMANCE)
>   		__set_bit(PLATFORM_PROFILE_PERFORMANCE, choices);
>   
> +	/* Make sure that ACPI is in sync with the profile set by USTT */
> +	current_mode = thermal_get_mode();
> +	if (current_mode < 0)
> +		return current_mode;
> +
> +	thermal_set_mode(current_mode);
> +
>   	return 0;
>   }
>   

Re: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS after reboot

[Lyndon Sanche]

On Tue, Sep 16, 2025, at 7:15 AM, Mario Limonciello wrote:
> On 9/16/25 6:51 AM, Shyam Sundar S K wrote:
>> After a reboot, if the user changes the thermal setting in the BIOS, the
>> BIOS applies this change. However, the current `dell-pc` driver does not
>> recognize the updated USTT value, resulting in inconsistent thermal
>> profiles between Windows and Linux.
>> 
>> To ensure alignment with Windows behavior, read the current USTT settings
>> during driver initialization and update the dell-pc USTT profile
>> accordingly whenever a change is detected.
>> 
>> Cc: Yijun Shen <Yijun.Shen@Dell.com>
>> Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
>> Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
>> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>> ---
>>   drivers/platform/x86/dell/dell-pc.c | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>> 
>> diff --git a/drivers/platform/x86/dell/dell-pc.c b/drivers/platform/x86/dell/dell-pc.c
>> index 48cc7511905a..becdd9aaef29 100644
>> --- a/drivers/platform/x86/dell/dell-pc.c
>> +++ b/drivers/platform/x86/dell/dell-pc.c
>> @@ -228,6 +228,8 @@ static int thermal_platform_profile_get(struct device *dev,
>>   
>>   static int thermal_platform_profile_probe(void *drvdata, unsigned long *choices)
>>   {
>> +	int current_mode;
>> +
>>   	if (supported_modes & DELL_QUIET)
>>   		__set_bit(PLATFORM_PROFILE_QUIET, choices);
>>   	if (supported_modes & DELL_COOL_BOTTOM)
>> @@ -237,6 +239,13 @@ static int thermal_platform_profile_probe(void *drvdata, unsigned long *choices)
>>   	if (supported_modes & DELL_PERFORMANCE)
>>   		__set_bit(PLATFORM_PROFILE_PERFORMANCE, choices);
>>   
>> +	/* Make sure that ACPI is in sync with the profile set by USTT */
>> +	current_mode = thermal_get_mode();
>> +	if (current_mode < 0)
>> +		return current_mode;
>> +
>> +	thermal_set_mode(current_mode);
>> +
>>   	return 0;
>>   }
>>

Thank you for this patch.

Reviewed-by: Lyndon Sanche <lsanche@lyndeno.ca>

RE: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS after reboot

[Shen, Yijun]

Internal Use - Confidential
> -----Original Message-----
> From: Lyndon Sanche <lsanche@lyndeno.ca>
> Sent: Wednesday, September 17, 2025 2:16 AM
> To: Mario Limonciello <superm1@kernel.org>; Shyam Sundar S K <Shyam-
> sundar.S-k@amd.com>; Hans de Goede <hdegoede@redhat.com>; Ilpo
> Järvinen <ilpo.jarvinen@linux.intel.com>
> Cc: platform-driver-x86@vger.kernel.org; Patil Rajesh
> <Patil.Reddy@amd.com>; Shen, Yijun <Yijun.Shen@dell.com>
> Subject: Re: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS
> after reboot
>
>
> [EXTERNAL EMAIL]
>
> On Tue, Sep 16, 2025, at 7:15 AM, Mario Limonciello wrote:
> > On 9/16/25 6:51 AM, Shyam Sundar S K wrote:
> >> After a reboot, if the user changes the thermal setting in the BIOS,
> >> the BIOS applies this change. However, the current `dell-pc` driver
> >> does not recognize the updated USTT value, resulting in inconsistent
> >> thermal profiles between Windows and Linux.
> >>
> >> To ensure alignment with Windows behavior, read the current USTT
> >> settings during driver initialization and update the dell-pc USTT
> >> profile accordingly whenever a change is detected.
> >>
> >> Cc: Yijun Shen <Yijun.Shen@Dell.com>
> >> Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
> >> Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
> >> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> > Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>> ---

Verified this patch on the issued system.

Tested-By: Yijun Shen <Yijun.Shen@Dell.com>

> >>   drivers/platform/x86/dell/dell-pc.c | 9 +++++++++
> >>   1 file changed, 9 insertions(+)
> >>
> >> diff --git a/drivers/platform/x86/dell/dell-pc.c
> >> b/drivers/platform/x86/dell/dell-pc.c
> >> index 48cc7511905a..becdd9aaef29 100644
> >> --- a/drivers/platform/x86/dell/dell-pc.c
> >> +++ b/drivers/platform/x86/dell/dell-pc.c
> >> @@ -228,6 +228,8 @@ static int thermal_platform_profile_get(struct
> >> device *dev,
> >>
> >>   static int thermal_platform_profile_probe(void *drvdata, unsigned long
> *choices)
> >>   {
> >> +  int current_mode;
> >> +
> >>    if (supported_modes & DELL_QUIET)
> >>            __set_bit(PLATFORM_PROFILE_QUIET, choices);
> >>    if (supported_modes & DELL_COOL_BOTTOM) @@ -237,6 +239,13
> @@
> >> static int thermal_platform_profile_probe(void *drvdata, unsigned long
> *choices)
> >>    if (supported_modes & DELL_PERFORMANCE)
> >>            __set_bit(PLATFORM_PROFILE_PERFORMANCE, choices);
> >>
> >> +  /* Make sure that ACPI is in sync with the profile set by USTT */
> >> +  current_mode = thermal_get_mode();
> >> +  if (current_mode < 0)
> >> +          return current_mode;
> >> +
> >> +  thermal_set_mode(current_mode);
> >> +
> >>    return 0;
> >>   }
> >>
>
> Thank you for this patch.
>
> Reviewed-by: Lyndon Sanche <lsanche@lyndeno.ca>

RE: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS after reboot

[Ilpo Järvinen]

[-- Attachment #1: Type: text/plain, Size: 3516 bytes --]

On Thu, 18 Sep 2025, Shen, Yijun wrote:

Hi Yijun,

> Internal Use - Confidential

You were posting this to a public mailing list and the usual custom is 
that Tested-by tags are recorded into the public git history of the 
kernel, which is incompatible with statements like this.

(I understand this line might have been auto-added by your company's email 
system without giving you a reasonable way to opt-out, so please clarify 
your intent.)

> > -----Original Message-----
> > From: Lyndon Sanche <lsanche@lyndeno.ca>
> > Sent: Wednesday, September 17, 2025 2:16 AM
> > To: Mario Limonciello <superm1@kernel.org>; Shyam Sundar S K <Shyam-
> > sundar.S-k@amd.com>; Hans de Goede <hdegoede@redhat.com>; Ilpo
> > Järvinen <ilpo.jarvinen@linux.intel.com>
> > Cc: platform-driver-x86@vger.kernel.org; Patil Rajesh
> > <Patil.Reddy@amd.com>; Shen, Yijun <Yijun.Shen@dell.com>
> > Subject: Re: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS
> > after reboot
> >
> >
> > [EXTERNAL EMAIL]
> >
> > On Tue, Sep 16, 2025, at 7:15 AM, Mario Limonciello wrote:
> > > On 9/16/25 6:51 AM, Shyam Sundar S K wrote:
> > >> After a reboot, if the user changes the thermal setting in the BIOS,
> > >> the BIOS applies this change. However, the current `dell-pc` driver
> > >> does not recognize the updated USTT value, resulting in inconsistent
> > >> thermal profiles between Windows and Linux.
> > >>
> > >> To ensure alignment with Windows behavior, read the current USTT
> > >> settings during driver initialization and update the dell-pc USTT
> > >> profile accordingly whenever a change is detected.
> > >>
> > >> Cc: Yijun Shen <Yijun.Shen@Dell.com>
> > >> Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
> > >> Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
> > >> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> > > Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>> ---
> 
> Verified this patch on the issued system.
> 
> Tested-By: Yijun Shen <Yijun.Shen@Dell.com>

Thanks for testing.

-- 
 i.

> > >>   drivers/platform/x86/dell/dell-pc.c | 9 +++++++++
> > >>   1 file changed, 9 insertions(+)
> > >>
> > >> diff --git a/drivers/platform/x86/dell/dell-pc.c
> > >> b/drivers/platform/x86/dell/dell-pc.c
> > >> index 48cc7511905a..becdd9aaef29 100644
> > >> --- a/drivers/platform/x86/dell/dell-pc.c
> > >> +++ b/drivers/platform/x86/dell/dell-pc.c
> > >> @@ -228,6 +228,8 @@ static int thermal_platform_profile_get(struct
> > >> device *dev,
> > >>
> > >>   static int thermal_platform_profile_probe(void *drvdata, unsigned long
> > *choices)
> > >>   {
> > >> +  int current_mode;
> > >> +
> > >>    if (supported_modes & DELL_QUIET)
> > >>            __set_bit(PLATFORM_PROFILE_QUIET, choices);
> > >>    if (supported_modes & DELL_COOL_BOTTOM) @@ -237,6 +239,13
> > @@
> > >> static int thermal_platform_profile_probe(void *drvdata, unsigned long
> > *choices)
> > >>    if (supported_modes & DELL_PERFORMANCE)
> > >>            __set_bit(PLATFORM_PROFILE_PERFORMANCE, choices);
> > >>
> > >> +  /* Make sure that ACPI is in sync with the profile set by USTT */
> > >> +  current_mode = thermal_get_mode();
> > >> +  if (current_mode < 0)
> > >> +          return current_mode;
> > >> +
> > >> +  thermal_set_mode(current_mode);
> > >> +
> > >>    return 0;
> > >>   }
> > >>
> >
> > Thank you for this patch.
> >
> > Reviewed-by: Lyndon Sanche <lsanche@lyndeno.ca>
> 

RE: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS after reboot

[Shen, Yijun]

> -----Original Message-----
> From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> Sent: Thursday, September 18, 2025 7:00 PM
> To: Shen, Yijun <Yijun.Shen@dell.com>
> Cc: Lyndon Sanche <lsanche@lyndeno.ca>; Mario Limonciello
> <superm1@kernel.org>; Shyam Sundar S K <Shyam-sundar.S-k@amd.com>;
> Hans de Goede <hdegoede@redhat.com>; platform-driver-
> x86@vger.kernel.org; Patil Rajesh <Patil.Reddy@amd.com>
> Subject: RE: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS
> after reboot
> 
> 
> [EXTERNAL EMAIL]
> 
> On Thu, 18 Sep 2025, Shen, Yijun wrote:
> 
> Hi Yijun,
> 
> > Internal Use - Confidential
> 
> You were posting this to a public mailing list and the usual custom is that
> Tested-by tags are recorded into the public git history of the kernel, which is
> incompatible with statements like this.
> 
> (I understand this line might have been auto-added by your company's email
> system without giving you a reasonable way to opt-out, so please clarify your
> intent.)
> 
Hi Ilpo,

 Sorry for the confusion. My "tested-by" mail is not for the "Internal Use",  it's Ok to added it into public git.
 I'll take care of such label issue while replying to a public mailing list next time.

Thanks

> > > -----Original Message-----
> > > From: Lyndon Sanche <lsanche@lyndeno.ca>
> > > Sent: Wednesday, September 17, 2025 2:16 AM
> > > To: Mario Limonciello <superm1@kernel.org>; Shyam Sundar S K <Shyam-
> > > sundar.S-k@amd.com>; Hans de Goede <hdegoede@redhat.com>; Ilpo
> > > Järvinen <ilpo.jarvinen@linux.intel.com>
> > > Cc: platform-driver-x86@vger.kernel.org; Patil Rajesh
> > > <Patil.Reddy@amd.com>; Shen, Yijun <Yijun.Shen@dell.com>
> > > Subject: Re: [PATCH v2] platform/x86/dell: Set USTT mode according
> > > to BIOS after reboot
> > >
> > >
> > > [EXTERNAL EMAIL]
> > >
> > > On Tue, Sep 16, 2025, at 7:15 AM, Mario Limonciello wrote:
> > > > On 9/16/25 6:51 AM, Shyam Sundar S K wrote:
> > > >> After a reboot, if the user changes the thermal setting in the
> > > >> BIOS, the BIOS applies this change. However, the current
> > > >> `dell-pc` driver does not recognize the updated USTT value,
> > > >> resulting in inconsistent thermal profiles between Windows and Linux.
> > > >>
> > > >> To ensure alignment with Windows behavior, read the current USTT
> > > >> settings during driver initialization and update the dell-pc USTT
> > > >> profile accordingly whenever a change is detected.
> > > >>
> > > >> Cc: Yijun Shen <Yijun.Shen@Dell.com>
> > > >> Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
> > > >> Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
> > > >> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> > > > Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>> ---
> >
> > Verified this patch on the issued system.
> >
> > Tested-By: Yijun Shen <Yijun.Shen@Dell.com>
> 
> Thanks for testing.
> 
> --
>  i.
> 
> > > >>   drivers/platform/x86/dell/dell-pc.c | 9 +++++++++
> > > >>   1 file changed, 9 insertions(+)
> > > >>
> > > >> diff --git a/drivers/platform/x86/dell/dell-pc.c
> > > >> b/drivers/platform/x86/dell/dell-pc.c
> > > >> index 48cc7511905a..becdd9aaef29 100644
> > > >> --- a/drivers/platform/x86/dell/dell-pc.c
> > > >> +++ b/drivers/platform/x86/dell/dell-pc.c
> > > >> @@ -228,6 +228,8 @@ static int
> > > >> thermal_platform_profile_get(struct
> > > >> device *dev,
> > > >>
> > > >>   static int thermal_platform_profile_probe(void *drvdata,
> > > >> unsigned long
> > > *choices)
> > > >>   {
> > > >> +  int current_mode;
> > > >> +
> > > >>    if (supported_modes & DELL_QUIET)
> > > >>            __set_bit(PLATFORM_PROFILE_QUIET, choices);
> > > >>    if (supported_modes & DELL_COOL_BOTTOM) @@ -237,6 +239,13
> > > @@
> > > >> static int thermal_platform_profile_probe(void *drvdata, unsigned
> > > >> long
> > > *choices)
> > > >>    if (supported_modes & DELL_PERFORMANCE)
> > > >>            __set_bit(PLATFORM_PROFILE_PERFORMANCE, choices);
> > > >>
> > > >> +  /* Make sure that ACPI is in sync with the profile set by USTT
> > > >> + */  current_mode = thermal_get_mode();  if (current_mode < 0)
> > > >> +          return current_mode;
> > > >> +
> > > >> +  thermal_set_mode(current_mode);
> > > >> +
> > > >>    return 0;
> > > >>   }
> > > >>
> > >
> > > Thank you for this patch.
> > >
> > > Reviewed-by: Lyndon Sanche <lsanche@lyndeno.ca>
> >

Re: [PATCH v2] platform/x86/dell: Set USTT mode according to BIOS after reboot

[Ilpo Järvinen]

On Tue, 16 Sep 2025 17:21:42 +0530, Shyam Sundar S K wrote:

> After a reboot, if the user changes the thermal setting in the BIOS, the
> BIOS applies this change. However, the current `dell-pc` driver does not
> recognize the updated USTT value, resulting in inconsistent thermal
> profiles between Windows and Linux.
> 
> To ensure alignment with Windows behavior, read the current USTT settings
> during driver initialization and update the dell-pc USTT profile
> accordingly whenever a change is detected.
> 
> [...]


Thank you for your contribution, it has been applied to my local
review-ilpo-fixes branch. Note it will show up in the public
platform-drivers-x86/review-ilpo-fixes branch only once I've pushed my
local branch there, which might take a while.

The list of commits applied:
[1/1] platform/x86/dell: Set USTT mode according to BIOS after reboot
      commit: 2c61c45af153243baf591a77ec187be2b9cfe302

--
 i.