| Message ID | 20241125093415.21719-2-lihuisong@huawei.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | hwmon: (acpi_power_meter) Some trival optimizations | expand |
On 11/25/24 01:34, Huisong Li wrote: > The 'power1_alarm' attribute uses the 'power' and 'cap' in the > acpi_power_meter_resource structure. However, these two fields are just > updated when user query 'power' and 'cap' attribute, or hardware enforced > limit. If user directly query the 'power1_alarm' attribute without queryng > above two attributes, driver will use the uninitialized variables to judge. > In addition, the 'power1_alarm' attribute needs to update power and cap to > show the real state. > > Signed-off-by: Huisong Li <lihuisong@huawei.com> > --- > drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c > index 2f1c9d97ad21..4c3314e35d30 100644 > --- a/drivers/hwmon/acpi_power_meter.c > +++ b/drivers/hwmon/acpi_power_meter.c > @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, > struct acpi_device *acpi_dev = to_acpi_device(dev); > struct acpi_power_meter_resource *resource = acpi_dev->driver_data; > u64 val = 0; > + int ret; > + > + guard(mutex)(&resource->lock); > > switch (attr->index) { > case 0: > @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, > val = 0; > break; > case 6: > + ret = update_meter(resource); > + if (ret) > + return ret; > + ret = update_cap(resource); > + if (ret) > + return ret; > + > if (resource->power > resource->cap) > val = 1; > else While technically correct, the implementation of this attribute defeats its purpose. It is supposed to reflect the current status as reported by the hardware. A real fix would be to use the associated notification to set or reset a status flag, and to report the current value of that flag as reported by the hardware. If there is no notification support, the attribute should not even exist, unless there is a means to retrieve its value from ACPI (the status itself, not by comparing temperature values). Guenter
Hi Guente, Thanks for your timely review. 在 2024/11/26 0:03, Guenter Roeck 写道: > On 11/25/24 01:34, Huisong Li wrote: >> The 'power1_alarm' attribute uses the 'power' and 'cap' in the >> acpi_power_meter_resource structure. However, these two fields are just >> updated when user query 'power' and 'cap' attribute, or hardware >> enforced >> limit. If user directly query the 'power1_alarm' attribute without >> queryng >> above two attributes, driver will use the uninitialized variables to >> judge. >> In addition, the 'power1_alarm' attribute needs to update power and >> cap to >> show the real state. >> >> Signed-off-by: Huisong Li <lihuisong@huawei.com> >> --- >> drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/hwmon/acpi_power_meter.c >> b/drivers/hwmon/acpi_power_meter.c >> index 2f1c9d97ad21..4c3314e35d30 100644 >> --- a/drivers/hwmon/acpi_power_meter.c >> +++ b/drivers/hwmon/acpi_power_meter.c >> @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, >> struct acpi_device *acpi_dev = to_acpi_device(dev); >> struct acpi_power_meter_resource *resource = >> acpi_dev->driver_data; >> u64 val = 0; >> + int ret; >> + >> + guard(mutex)(&resource->lock); >> switch (attr->index) { >> case 0: >> @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, >> val = 0; >> break; >> case 6: >> + ret = update_meter(resource); >> + if (ret) >> + return ret; >> + ret = update_cap(resource); >> + if (ret) >> + return ret; >> + >> if (resource->power > resource->cap) >> val = 1; >> else > > > While technically correct, the implementation of this attribute > defeats its > purpose. It is supposed to reflect the current status as reported by the > hardware. A real fix would be to use the associated notification to > set or > reset a status flag, and to report the current value of that flag as > reported > by the hardware. I know what you mean. The Notify(power_meter, 0x83) is supposed to meet your proposal IIUC. It's good, but it depands on hardware support notification. > > If there is no notification support, the attribute should not even exist, > unless there is a means to retrieve its value from ACPI (the status > itself, > not by comparing temperature values). Currently, the 'power1_alarm' attribute is created just when platform support the power meter meassurement(bit0 of the supported capabilities in _PMC). And it doesn't see if the platform support notifications. From the current implementation of this driver, this sysfs can also reflect the status by comparing power and cap, which is good to the platform that support hardware limit from some out-of-band mechanism but doesn't support any notification.
On 11/25/24 17:56, lihuisong (C) wrote: > Hi Guente, > > Thanks for your timely review. > > 在 2024/11/26 0:03, Guenter Roeck 写道: >> On 11/25/24 01:34, Huisong Li wrote: >>> The 'power1_alarm' attribute uses the 'power' and 'cap' in the >>> acpi_power_meter_resource structure. However, these two fields are just >>> updated when user query 'power' and 'cap' attribute, or hardware enforced >>> limit. If user directly query the 'power1_alarm' attribute without queryng >>> above two attributes, driver will use the uninitialized variables to judge. >>> In addition, the 'power1_alarm' attribute needs to update power and cap to >>> show the real state. >>> >>> Signed-off-by: Huisong Li <lihuisong@huawei.com> >>> --- >>> drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ >>> 1 file changed, 10 insertions(+) >>> >>> diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c >>> index 2f1c9d97ad21..4c3314e35d30 100644 >>> --- a/drivers/hwmon/acpi_power_meter.c >>> +++ b/drivers/hwmon/acpi_power_meter.c >>> @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, >>> struct acpi_device *acpi_dev = to_acpi_device(dev); >>> struct acpi_power_meter_resource *resource = acpi_dev->driver_data; >>> u64 val = 0; >>> + int ret; >>> + >>> + guard(mutex)(&resource->lock); >>> switch (attr->index) { >>> case 0: >>> @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, >>> val = 0; >>> break; >>> case 6: >>> + ret = update_meter(resource); >>> + if (ret) >>> + return ret; >>> + ret = update_cap(resource); >>> + if (ret) >>> + return ret; >>> + >>> if (resource->power > resource->cap) >>> val = 1; >>> else >> >> >> While technically correct, the implementation of this attribute defeats its >> purpose. It is supposed to reflect the current status as reported by the >> hardware. A real fix would be to use the associated notification to set or >> reset a status flag, and to report the current value of that flag as reported >> by the hardware. > I know what you mean. > The Notify(power_meter, 0x83) is supposed to meet your proposal IIUC. > It's good, but it depands on hardware support notification. >> >> If there is no notification support, the attribute should not even exist, >> unless there is a means to retrieve its value from ACPI (the status itself, >> not by comparing temperature values). > Currently, the 'power1_alarm' attribute is created just when platform support the power meter meassurement(bit0 of the supported capabilities in _PMC). > And it doesn't see if the platform support notifications. > From the current implementation of this driver, this sysfs can also reflect the status by comparing power and cap, > which is good to the platform that support hardware limit from some out-of-band mechanism but doesn't support any notification. > The point is that this can also be done from userspace. Hardware monitoring drivers are supposed to provide hardware attributes, not software attributes derived from it. Guenter
在 2024/11/26 12:04, Guenter Roeck 写道: > On 11/25/24 17:56, lihuisong (C) wrote: >> Hi Guente, >> >> Thanks for your timely review. >> >> 在 2024/11/26 0:03, Guenter Roeck 写道: >>> On 11/25/24 01:34, Huisong Li wrote: >>>> The 'power1_alarm' attribute uses the 'power' and 'cap' in the >>>> acpi_power_meter_resource structure. However, these two fields are >>>> just >>>> updated when user query 'power' and 'cap' attribute, or hardware >>>> enforced >>>> limit. If user directly query the 'power1_alarm' attribute without >>>> queryng >>>> above two attributes, driver will use the uninitialized variables >>>> to judge. >>>> In addition, the 'power1_alarm' attribute needs to update power and >>>> cap to >>>> show the real state. >>>> >>>> Signed-off-by: Huisong Li <lihuisong@huawei.com> >>>> --- >>>> drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ >>>> 1 file changed, 10 insertions(+) >>>> >>>> diff --git a/drivers/hwmon/acpi_power_meter.c >>>> b/drivers/hwmon/acpi_power_meter.c >>>> index 2f1c9d97ad21..4c3314e35d30 100644 >>>> --- a/drivers/hwmon/acpi_power_meter.c >>>> +++ b/drivers/hwmon/acpi_power_meter.c >>>> @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, >>>> struct acpi_device *acpi_dev = to_acpi_device(dev); >>>> struct acpi_power_meter_resource *resource = >>>> acpi_dev->driver_data; >>>> u64 val = 0; >>>> + int ret; >>>> + >>>> + guard(mutex)(&resource->lock); >>>> switch (attr->index) { >>>> case 0: >>>> @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, >>>> val = 0; >>>> break; >>>> case 6: >>>> + ret = update_meter(resource); >>>> + if (ret) >>>> + return ret; >>>> + ret = update_cap(resource); >>>> + if (ret) >>>> + return ret; >>>> + >>>> if (resource->power > resource->cap) >>>> val = 1; >>>> else >>> >>> >>> While technically correct, the implementation of this attribute >>> defeats its >>> purpose. It is supposed to reflect the current status as reported by >>> the >>> hardware. A real fix would be to use the associated notification to >>> set or >>> reset a status flag, and to report the current value of that flag as >>> reported >>> by the hardware. >> I know what you mean. >> The Notify(power_meter, 0x83) is supposed to meet your proposal IIUC. >> It's good, but it depands on hardware support notification. >>> >>> If there is no notification support, the attribute should not even >>> exist, >>> unless there is a means to retrieve its value from ACPI (the status >>> itself, >>> not by comparing temperature values). >> Currently, the 'power1_alarm' attribute is created just when platform >> support the power meter meassurement(bit0 of the supported >> capabilities in _PMC). >> And it doesn't see if the platform support notifications. >> From the current implementation of this driver, this sysfs can also >> reflect the status by comparing power and cap, >> which is good to the platform that support hardware limit from some >> out-of-band mechanism but doesn't support any notification. >> > > The point is that this can also be done from userspace. Hardware > monitoring drivers > are supposed to provide hardware attributes, not software attributes > derived from it. > So this 'power1_alarm' attribute can be exposed when platform supports hardware enforced limit and notifcations when the hardware limit is enforced, right? If so, we have to change the condition that driver creates this sysfs interface. > > > .
On 11/25/24 23:03, lihuisong (C) wrote: > > 在 2024/11/26 12:04, Guenter Roeck 写道: >> On 11/25/24 17:56, lihuisong (C) wrote: >>> Hi Guente, >>> >>> Thanks for your timely review. >>> >>> 在 2024/11/26 0:03, Guenter Roeck 写道: >>>> On 11/25/24 01:34, Huisong Li wrote: >>>>> The 'power1_alarm' attribute uses the 'power' and 'cap' in the >>>>> acpi_power_meter_resource structure. However, these two fields are just >>>>> updated when user query 'power' and 'cap' attribute, or hardware enforced >>>>> limit. If user directly query the 'power1_alarm' attribute without queryng >>>>> above two attributes, driver will use the uninitialized variables to judge. >>>>> In addition, the 'power1_alarm' attribute needs to update power and cap to >>>>> show the real state. >>>>> >>>>> Signed-off-by: Huisong Li <lihuisong@huawei.com> >>>>> --- >>>>> drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ >>>>> 1 file changed, 10 insertions(+) >>>>> >>>>> diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c >>>>> index 2f1c9d97ad21..4c3314e35d30 100644 >>>>> --- a/drivers/hwmon/acpi_power_meter.c >>>>> +++ b/drivers/hwmon/acpi_power_meter.c >>>>> @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, >>>>> struct acpi_device *acpi_dev = to_acpi_device(dev); >>>>> struct acpi_power_meter_resource *resource = acpi_dev->driver_data; >>>>> u64 val = 0; >>>>> + int ret; >>>>> + >>>>> + guard(mutex)(&resource->lock); >>>>> switch (attr->index) { >>>>> case 0: >>>>> @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, >>>>> val = 0; >>>>> break; >>>>> case 6: >>>>> + ret = update_meter(resource); >>>>> + if (ret) >>>>> + return ret; >>>>> + ret = update_cap(resource); >>>>> + if (ret) >>>>> + return ret; >>>>> + >>>>> if (resource->power > resource->cap) >>>>> val = 1; >>>>> else >>>> >>>> >>>> While technically correct, the implementation of this attribute defeats its >>>> purpose. It is supposed to reflect the current status as reported by the >>>> hardware. A real fix would be to use the associated notification to set or >>>> reset a status flag, and to report the current value of that flag as reported >>>> by the hardware. >>> I know what you mean. >>> The Notify(power_meter, 0x83) is supposed to meet your proposal IIUC. >>> It's good, but it depands on hardware support notification. >>>> >>>> If there is no notification support, the attribute should not even exist, >>>> unless there is a means to retrieve its value from ACPI (the status itself, >>>> not by comparing temperature values). >>> Currently, the 'power1_alarm' attribute is created just when platform support the power meter meassurement(bit0 of the supported capabilities in _PMC). >>> And it doesn't see if the platform support notifications. >>> From the current implementation of this driver, this sysfs can also reflect the status by comparing power and cap, >>> which is good to the platform that support hardware limit from some out-of-band mechanism but doesn't support any notification. >>> >> >> The point is that this can also be done from userspace. Hardware monitoring drivers >> are supposed to provide hardware attributes, not software attributes derived from it. >> > So this 'power1_alarm' attribute can be exposed when platform supports hardware enforced limit and notifcations when the hardware limit is enforced, right? > If so, we have to change the condition that driver creates this sysfs interface. This isn't about enforcing anything, it is about reporting an alarm if the power consumed exceeds the maximum configured. Guenter
在 2024/11/27 0:19, Guenter Roeck 写道: > On 11/25/24 23:03, lihuisong (C) wrote: >> >> 在 2024/11/26 12:04, Guenter Roeck 写道: >>> On 11/25/24 17:56, lihuisong (C) wrote: >>>> Hi Guente, >>>> >>>> Thanks for your timely review. >>>> >>>> 在 2024/11/26 0:03, Guenter Roeck 写道: >>>>> On 11/25/24 01:34, Huisong Li wrote: >>>>>> The 'power1_alarm' attribute uses the 'power' and 'cap' in the >>>>>> acpi_power_meter_resource structure. However, these two fields >>>>>> are just >>>>>> updated when user query 'power' and 'cap' attribute, or hardware >>>>>> enforced >>>>>> limit. If user directly query the 'power1_alarm' attribute >>>>>> without queryng >>>>>> above two attributes, driver will use the uninitialized variables >>>>>> to judge. >>>>>> In addition, the 'power1_alarm' attribute needs to update power >>>>>> and cap to >>>>>> show the real state. >>>>>> >>>>>> Signed-off-by: Huisong Li <lihuisong@huawei.com> >>>>>> --- >>>>>> drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ >>>>>> 1 file changed, 10 insertions(+) >>>>>> >>>>>> diff --git a/drivers/hwmon/acpi_power_meter.c >>>>>> b/drivers/hwmon/acpi_power_meter.c >>>>>> index 2f1c9d97ad21..4c3314e35d30 100644 >>>>>> --- a/drivers/hwmon/acpi_power_meter.c >>>>>> +++ b/drivers/hwmon/acpi_power_meter.c >>>>>> @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, >>>>>> struct acpi_device *acpi_dev = to_acpi_device(dev); >>>>>> struct acpi_power_meter_resource *resource = >>>>>> acpi_dev->driver_data; >>>>>> u64 val = 0; >>>>>> + int ret; >>>>>> + >>>>>> + guard(mutex)(&resource->lock); >>>>>> switch (attr->index) { >>>>>> case 0: >>>>>> @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, >>>>>> val = 0; >>>>>> break; >>>>>> case 6: >>>>>> + ret = update_meter(resource); >>>>>> + if (ret) >>>>>> + return ret; >>>>>> + ret = update_cap(resource); >>>>>> + if (ret) >>>>>> + return ret; >>>>>> + >>>>>> if (resource->power > resource->cap) >>>>>> val = 1; >>>>>> else >>>>> >>>>> >>>>> While technically correct, the implementation of this attribute >>>>> defeats its >>>>> purpose. It is supposed to reflect the current status as reported >>>>> by the >>>>> hardware. A real fix would be to use the associated notification >>>>> to set or >>>>> reset a status flag, and to report the current value of that flag >>>>> as reported >>>>> by the hardware. >>>> I know what you mean. >>>> The Notify(power_meter, 0x83) is supposed to meet your proposal IIUC. >>>> It's good, but it depands on hardware support notification. >>>>> >>>>> If there is no notification support, the attribute should not even >>>>> exist, >>>>> unless there is a means to retrieve its value from ACPI (the >>>>> status itself, >>>>> not by comparing temperature values). >>>> Currently, the 'power1_alarm' attribute is created just when >>>> platform support the power meter meassurement(bit0 of the supported >>>> capabilities in _PMC). >>>> And it doesn't see if the platform support notifications. >>>> From the current implementation of this driver, this sysfs can >>>> also reflect the status by comparing power and cap, >>>> which is good to the platform that support hardware limit from some >>>> out-of-band mechanism but doesn't support any notification. >>>> >>> >>> The point is that this can also be done from userspace. Hardware >>> monitoring drivers >>> are supposed to provide hardware attributes, not software attributes >>> derived from it. >>> >> So this 'power1_alarm' attribute can be exposed when platform >> supports hardware enforced limit and notifcations when the hardware >> limit is enforced, right? >> If so, we have to change the condition that driver creates this sysfs >> interface. > > This isn't about enforcing anything, it is about reporting an alarm > if the power consumed exceeds the maximum configured. > Sorry, I don't quite understand what you mean. What your mean is to delete the current 'power1_alarm' sysfs and just use the related notify event to user? How should we fix this issue? /Huisong > > .
Hi Guenter， How about the modification as below? But driver doesn't know what the time is to set resource->power_alarm to false. 在 2024/11/27 0:19, Guenter Roeck 写道: > On 11/25/24 23:03, lihuisong (C) wrote: >> >> 在 2024/11/26 12:04, Guenter Roeck 写道: >>> On 11/25/24 17:56, lihuisong (C) wrote: >>>> Hi Guente, >>>> >>>> Thanks for your timely review. >>>> >>>> 在 2024/11/26 0:03, Guenter Roeck 写道: >>>>> On 11/25/24 01:34, Huisong Li wrote: >>>>>> The 'power1_alarm' attribute uses the 'power' and 'cap' in the >>>>>> acpi_power_meter_resource structure. However, these two fields >>>>>> are just >>>>>> updated when user query 'power' and 'cap' attribute, or hardware >>>>>> enforced >>>>>> limit. If user directly query the 'power1_alarm' attribute >>>>>> without queryng >>>>>> above two attributes, driver will use the uninitialized variables >>>>>> to judge. >>>>>> In addition, the 'power1_alarm' attribute needs to update power >>>>>> and cap to >>>>>> show the real state. >>>>>> >>>>>> Signed-off-by: Huisong Li <lihuisong@huawei.com> >>>>>> --- >>>>>> drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ >>>>>> 1 file changed, 10 insertions(+) >>>>>> >>>>>> diff --git a/drivers/hwmon/acpi_power_meter.c >>>>>> b/drivers/hwmon/acpi_power_meter.c >>>>>> index 2f1c9d97ad21..4c3314e35d30 100644 >>>>>> --- a/drivers/hwmon/acpi_power_meter.c >>>>>> +++ b/drivers/hwmon/acpi_power_meter.c >>>>>> @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, >>>>>> struct acpi_device *acpi_dev = to_acpi_device(dev); >>>>>> struct acpi_power_meter_resource *resource = >>>>>> acpi_dev->driver_data; >>>>>> u64 val = 0; >>>>>> + int ret; >>>>>> + >>>>>> + guard(mutex)(&resource->lock); >>>>>> switch (attr->index) { >>>>>> case 0: >>>>>> @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, >>>>>> val = 0; >>>>>> break; >>>>>> case 6: >>>>>> + ret = update_meter(resource); >>>>>> + if (ret) >>>>>> + return ret; >>>>>> + ret = update_cap(resource); >>>>>> + if (ret) >>>>>> + return ret; >>>>>> + >>>>>> if (resource->power > resource->cap) >>>>>> val = 1; >>>>>> else >>>>> >>>>> >>>>> While technically correct, the implementation of this attribute >>>>> defeats its >>>>> purpose. It is supposed to reflect the current status as reported >>>>> by the >>>>> hardware. A real fix would be to use the associated notification >>>>> to set or >>>>> reset a status flag, and to report the current value of that flag >>>>> as reported >>>>> by the hardware. >>>> I know what you mean. >>>> The Notify(power_meter, 0x83) is supposed to meet your proposal IIUC. >>>> It's good, but it depands on hardware support notification. >>>>> >>>>> If there is no notification support, the attribute should not even >>>>> exist, >>>>> unless there is a means to retrieve its value from ACPI (the >>>>> status itself, >>>>> not by comparing temperature values). >>>> Currently, the 'power1_alarm' attribute is created just when >>>> platform support the power meter meassurement(bit0 of the supported >>>> capabilities in _PMC). >>>> And it doesn't see if the platform support notifications. >>>> From the current implementation of this driver, this sysfs can >>>> also reflect the status by comparing power and cap, >>>> which is good to the platform that support hardware limit from some >>>> out-of-band mechanism but doesn't support any notification. >>>> >>> >>> The point is that this can also be done from userspace. Hardware >>> monitoring drivers >>> are supposed to provide hardware attributes, not software attributes >>> derived from it. >>> >> So this 'power1_alarm' attribute can be exposed when platform >> supports hardware enforced limit and notifcations when the hardware >> limit is enforced, right? >> If so, we have to change the condition that driver creates this sysfs >> interface. > > This isn't about enforcing anything, it is about reporting an alarm > if the power consumed exceeds the maximum configured. > --> index 2f1c9d97ad21..b436ebd863e6 --- a/drivers/hwmon/acpi_power_meter.c +++ b/drivers/hwmon/acpi_power_meter.c @@ -84,6 +84,7 @@ struct acpi_power_meter_resource { u64 power; u64 cap; u64 avg_interval; + bool power_alarm; int sensors_valid; unsigned long sensors_last_updated; struct sensor_device_attribute sensors[NUM_SENSORS]; @@ -396,6 +397,9 @@ static ssize_t show_val(struct device *dev, struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; u64 val = 0; + int ret; + + guard(mutex)(&resource->lock); switch (attr->index) { case 0: @@ -423,10 +427,21 @@ static ssize_t show_val(struct device *dev, val = 0; break; case 6: - if (resource->power > resource->cap) - val = 1; - else - val = 0; + /* report alarm status based on the notification if support. */ + if (resource->caps.flags & POWER_METER_CAN_NOTIFY) { + val = resource->power_alarm; + } else { + ret = update_meter(resource); + if (ret) + return ret; + ret = update_cap(resource); + if (ret) + return ret; + if (resource->power > resource->cap) + val = 1; + else + val = 0; + } break; case 7: case 8: @@ -853,6 +868,7 @@ static void acpi_power_meter_notify(struct acpi_device *device, u32 event) sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME); break; case METER_NOTIFY_CAPPING: + resource->power_alarm = true; sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME); dev_info(&device->dev, "Capping in progress.\n"); break; > .
diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c index 2f1c9d97ad21..4c3314e35d30 100644 --- a/drivers/hwmon/acpi_power_meter.c +++ b/drivers/hwmon/acpi_power_meter.c @@ -396,6 +396,9 @@ static ssize_t show_val(struct device *dev, struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; u64 val = 0; + int ret; + + guard(mutex)(&resource->lock); switch (attr->index) { case 0: @@ -423,6 +426,13 @@ static ssize_t show_val(struct device *dev, val = 0; break; case 6: + ret = update_meter(resource); + if (ret) + return ret; + ret = update_cap(resource); + if (ret) + return ret; + if (resource->power > resource->cap) val = 1; else
The 'power1_alarm' attribute uses the 'power' and 'cap' in the acpi_power_meter_resource structure. However, these two fields are just updated when user query 'power' and 'cap' attribute, or hardware enforced limit. If user directly query the 'power1_alarm' attribute without queryng above two attributes, driver will use the uninitialized variables to judge. In addition, the 'power1_alarm' attribute needs to update power and cap to show the real state. Signed-off-by: Huisong Li <lihuisong@huawei.com> --- drivers/hwmon/acpi_power_meter.c | 10 ++++++++++ 1 file changed, 10 insertions(+)