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[PATCH 1/2] power: supply: Use the scope of power supplies to tell if power is system supplied

Mario Limonciello posted 2 patches 2 years, 8 months ago
[PATCH 1/2] power: supply: Use the scope of power supplies to tell if power is system supplied
Posted by Mario Limonciello 2 years, 8 months ago 
The logic used for power_supply_is_system_supplied() counts all power
supplies and:
* If no power supplies found assumes AC
* If non-battery power supplies found uses online to determine AC/DC.
  - If any are onlined, assumes AC
  - Othewise DC.

This logic makes sense for desktop systems that don't export an ACPI
battery, but it fails once you include a dGPU that provides a UCSI
power supply on a desktop system without any other power supplies.

The dGPU by default doesn't have anything plugged in so it's 'offline'.
This makes power_supply_is_system_supplied() return 0 with a count of
1 meaning all drivers that use this get a wrong judgement.

To fix this case adjust the logic to also examine the scope of the
power supply. If the power supply is deemed a device power supply,
then don't count it.

Cc: Evan Quan <Evan.Quan@amd.com>
Suggested-by: Lijo Lazar <Lijo.Lazar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/power/supply/power_supply_core.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index ab986dbace16..d57f420ba8c3 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -348,6 +348,10 @@ static int __power_supply_is_system_supplied(struct device *dev, void *data)
 	struct power_supply *psy = dev_get_drvdata(dev);
 	unsigned int *count = data;
 
+	if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_SCOPE, &ret))
+		if (ret.intval == POWER_SUPPLY_SCOPE_DEVICE)
+			return 0;
+
 	(*count)++;
 	if (psy->desc->type != POWER_SUPPLY_TYPE_BATTERY)
 		if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_ONLINE,
@@ -366,8 +370,8 @@ int power_supply_is_system_supplied(void)
 				      __power_supply_is_system_supplied);
 
 	/*
-	 * If no power class device was found at all, most probably we are
-	 * running on a desktop system, so assume we are on mains power.
+	 * If no system scope power class device was found at all, most probably we
+	 * are running on a desktop system, so assume we are on mains power.
 	 */
 	if (count == 0)
 		return 1;
-- 
2.34.1
Re: [PATCH 1/2] power: supply: Use the scope of power supplies to tell if power is system supplied
Posted by Sebastian Reichel 2 years, 8 months ago 
Hi,

On Tue, May 16, 2023 at 01:25:40PM -0500, Mario Limonciello wrote:
> The logic used for power_supply_is_system_supplied() counts all power
> supplies and:
> * If no power supplies found assumes AC
> * If non-battery power supplies found uses online to determine AC/DC.
>   - If any are onlined, assumes AC
>   - Othewise DC.
> 
> This logic makes sense for desktop systems that don't export an ACPI
> battery, but it fails once you include a dGPU that provides a UCSI
> power supply on a desktop system without any other power supplies.
> 
> The dGPU by default doesn't have anything plugged in so it's 'offline'.
> This makes power_supply_is_system_supplied() return 0 with a count of
> 1 meaning all drivers that use this get a wrong judgement.
> 
> To fix this case adjust the logic to also examine the scope of the
> power supply. If the power supply is deemed a device power supply,
> then don't count it.
> 
> Cc: Evan Quan <Evan.Quan@amd.com>
> Suggested-by: Lijo Lazar <Lijo.Lazar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---

Good find; the current logic should also break with a desktop PC
once a POWER_SUPPLY_SCOPE_DEVICE battery device is attached (e.g.
a HID device), because it increases the counter.

I suppose I can just apply this to my fixes branch since there is
no compile time dependency to the second patch?

-- Sebastian

>  drivers/power/supply/power_supply_core.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
> index ab986dbace16..d57f420ba8c3 100644
> --- a/drivers/power/supply/power_supply_core.c
> +++ b/drivers/power/supply/power_supply_core.c
> @@ -348,6 +348,10 @@ static int __power_supply_is_system_supplied(struct device *dev, void *data)
>  	struct power_supply *psy = dev_get_drvdata(dev);
>  	unsigned int *count = data;
>  
> +	if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_SCOPE, &ret))
> +		if (ret.intval == POWER_SUPPLY_SCOPE_DEVICE)
> +			return 0;
> +
>  	(*count)++;
>  	if (psy->desc->type != POWER_SUPPLY_TYPE_BATTERY)
>  		if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_ONLINE,
> @@ -366,8 +370,8 @@ int power_supply_is_system_supplied(void)
>  				      __power_supply_is_system_supplied);
>  
>  	/*
> -	 * If no power class device was found at all, most probably we are
> -	 * running on a desktop system, so assume we are on mains power.
> +	 * If no system scope power class device was found at all, most probably we
> +	 * are running on a desktop system, so assume we are on mains power.
>  	 */
>  	if (count == 0)
>  		return 1;
> -- 
> 2.34.1
>
Re: [PATCH 1/2] power: supply: Use the scope of power supplies to tell if power is system supplied
Posted by Limonciello, Mario 2 years, 8 months ago 
On 5/16/2023 3:41 PM, Sebastian Reichel wrote:
> Hi,
>
> On Tue, May 16, 2023 at 01:25:40PM -0500, Mario Limonciello wrote:
>> The logic used for power_supply_is_system_supplied() counts all power
>> supplies and:
>> * If no power supplies found assumes AC
>> * If non-battery power supplies found uses online to determine AC/DC.
>>    - If any are onlined, assumes AC
>>    - Othewise DC.
>>
>> This logic makes sense for desktop systems that don't export an ACPI
>> battery, but it fails once you include a dGPU that provides a UCSI
>> power supply on a desktop system without any other power supplies.
>>
>> The dGPU by default doesn't have anything plugged in so it's 'offline'.
>> This makes power_supply_is_system_supplied() return 0 with a count of
>> 1 meaning all drivers that use this get a wrong judgement.
>>
>> To fix this case adjust the logic to also examine the scope of the
>> power supply. If the power supply is deemed a device power supply,
>> then don't count it.
>>
>> Cc: Evan Quan <Evan.Quan@amd.com>
>> Suggested-by: Lijo Lazar <Lijo.Lazar@amd.com>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
> Good find; the current logic should also break with a desktop PC
> once a POWER_SUPPLY_SCOPE_DEVICE battery device is attached (e.g.
> a HID device), because it increases the counter.

Yup!

> I suppose I can just apply this to my fixes branch since there is
> no compile time dependency to the second patch?

Yes, that's correct.  I don't see a problem with the other patch going 
through
another tree.

> -- Sebastian
>
>>   drivers/power/supply/power_supply_core.c | 8 ++++++--
>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
>> index ab986dbace16..d57f420ba8c3 100644
>> --- a/drivers/power/supply/power_supply_core.c
>> +++ b/drivers/power/supply/power_supply_core.c
>> @@ -348,6 +348,10 @@ static int __power_supply_is_system_supplied(struct device *dev, void *data)
>>   	struct power_supply *psy = dev_get_drvdata(dev);
>>   	unsigned int *count = data;
>>   
>> +	if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_SCOPE, &ret))
>> +		if (ret.intval == POWER_SUPPLY_SCOPE_DEVICE)
>> +			return 0;
>> +
>>   	(*count)++;
>>   	if (psy->desc->type != POWER_SUPPLY_TYPE_BATTERY)
>>   		if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_ONLINE,
>> @@ -366,8 +370,8 @@ int power_supply_is_system_supplied(void)
>>   				      __power_supply_is_system_supplied);
>>   
>>   	/*
>> -	 * If no power class device was found at all, most probably we are
>> -	 * running on a desktop system, so assume we are on mains power.
>> +	 * If no system scope power class device was found at all, most probably we
>> +	 * are running on a desktop system, so assume we are on mains power.
>>   	 */
>>   	if (count == 0)
>>   		return 1;
>> -- 
>> 2.34.1
>>
Re: [PATCH 1/2] power: supply: Use the scope of power supplies to tell if power is system supplied
Posted by Sebastian Reichel 2 years, 8 months ago 
Hi,

On Tue, May 16, 2023 at 03:44:17PM -0500, Limonciello, Mario wrote:
> On 5/16/2023 3:41 PM, Sebastian Reichel wrote:
> > Hi,
> > 
> > On Tue, May 16, 2023 at 01:25:40PM -0500, Mario Limonciello wrote:
> > > The logic used for power_supply_is_system_supplied() counts all power
> > > supplies and:
> > > * If no power supplies found assumes AC
> > > * If non-battery power supplies found uses online to determine AC/DC.
> > >    - If any are onlined, assumes AC
> > >    - Othewise DC.
> > > 
> > > This logic makes sense for desktop systems that don't export an ACPI
> > > battery, but it fails once you include a dGPU that provides a UCSI
> > > power supply on a desktop system without any other power supplies.
> > > 
> > > The dGPU by default doesn't have anything plugged in so it's 'offline'.
> > > This makes power_supply_is_system_supplied() return 0 with a count of
> > > 1 meaning all drivers that use this get a wrong judgement.
> > > 
> > > To fix this case adjust the logic to also examine the scope of the
> > > power supply. If the power supply is deemed a device power supply,
> > > then don't count it.
> > > 
> > > Cc: Evan Quan <Evan.Quan@amd.com>
> > > Suggested-by: Lijo Lazar <Lijo.Lazar@amd.com>
> > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> > > ---
> > Good find; the current logic should also break with a desktop PC
> > once a POWER_SUPPLY_SCOPE_DEVICE battery device is attached (e.g.
> > a HID device), because it increases the counter.
> 
> Yup!
> 
> > I suppose I can just apply this to my fixes branch since there is
> > no compile time dependency to the second patch?
> 
> Yes, that's correct.  I don't see a problem with the other patch going
> through another tree.

Ok, I modified the commit message to also mention the HID issue and
applied it to power-supply's fixes branch.

Thanks,

-- Sebastian

> 
> > -- Sebastian
> > 
> > >   drivers/power/supply/power_supply_core.c | 8 ++++++--
> > >   1 file changed, 6 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
> > > index ab986dbace16..d57f420ba8c3 100644
> > > --- a/drivers/power/supply/power_supply_core.c
> > > +++ b/drivers/power/supply/power_supply_core.c
> > > @@ -348,6 +348,10 @@ static int __power_supply_is_system_supplied(struct device *dev, void *data)
> > >   	struct power_supply *psy = dev_get_drvdata(dev);
> > >   	unsigned int *count = data;
> > > +	if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_SCOPE, &ret))
> > > +		if (ret.intval == POWER_SUPPLY_SCOPE_DEVICE)
> > > +			return 0;
> > > +
> > >   	(*count)++;
> > >   	if (psy->desc->type != POWER_SUPPLY_TYPE_BATTERY)
> > >   		if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_ONLINE,
> > > @@ -366,8 +370,8 @@ int power_supply_is_system_supplied(void)
> > >   				      __power_supply_is_system_supplied);
> > >   	/*
> > > -	 * If no power class device was found at all, most probably we are
> > > -	 * running on a desktop system, so assume we are on mains power.
> > > +	 * If no system scope power class device was found at all, most probably we
> > > +	 * are running on a desktop system, so assume we are on mains power.
> > >   	 */
> > >   	if (count == 0)
> > >   		return 1;
> > > -- 
> > > 2.34.1
> > >

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