linux-kernel - Re: [PATCH v2 4/4] hwmon: (pmbus/core): Notify hwmon events

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Date:   Tue, 14 Feb 2023 19:41:45 +0530
From:   Naresh Solanki <naresh.solanki@...ements.com>
To:     Guenter Roeck <linux@...ck-us.net>
Cc:     Jean Delvare <jdelvare@...e.com>, linux-hwmon@...r.kernel.org,
        Patrick Rudolph <patrick.rudolph@...ements.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 4/4] hwmon: (pmbus/core): Notify hwmon events

Hi,

On 11-02-2023 09:16 pm, Guenter Roeck wrote:
> On Tue, Feb 07, 2023 at 01:02:41PM +0100, Naresh Solanki wrote:
>> From: Patrick Rudolph <patrick.rudolph@...ements.com>
>>
>> Notify hwmon events using the pmbus irq handler.
>>
>> Signed-off-by: Patrick Rudolph <patrick.rudolph@...ements.com>
>> Signed-off-by: Naresh Solanki <Naresh.Solanki@...ements.com>
>> ...
>> Changes in V2
>> - Remove __maybe_unsed attribute as its not needed.
>> ---
>>   drivers/hwmon/pmbus/pmbus_core.c | 48 ++++++++++++++++++++++++++++----
>>   1 file changed, 43 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
>> index d5403baad60a..f6778a9c7126 100644
>> --- a/drivers/hwmon/pmbus/pmbus_core.c
>> +++ b/drivers/hwmon/pmbus/pmbus_core.c
>> @@ -2735,8 +2735,36 @@ static const struct pmbus_status_category __maybe_unused pmbus_status_flag_map[]
>>   	},
>>   };
>>   
>> +#define to_dev_attr(_dev_attr) \
>> +	container_of(_dev_attr, struct device_attribute, attr)
>> +
>> +static void pmbus_notify(struct pmbus_data *data, int page, int reg, int flags)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < data->num_attributes; i++) {
>> +		struct device_attribute *da = to_dev_attr(data->group.attrs[i]);
>> +		struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
>> +		int index = attr->index;
>> +		u16 smask = pb_index_to_mask(index);
>> +		u8 spage = pb_index_to_page(index);
>> +		u16 sreg = pb_index_to_reg(index);
>> +
>> +		if (reg == sreg && page == spage && (smask & flags)) {
>> +			dev_dbg(data->dev, "sysfs notify: %s", da->attr.name);
>> +			sysfs_notify(&data->dev->kobj, NULL, da->attr.name);
>> +			kobject_uevent(&data->dev->kobj, KOBJ_CHANGE);
>> +			flags &= ~smask;
>> +		}
>> +
>> +		if (!flags)
>> +			break;
>> +	}
>> +}
>> +
>> +static int pmbus_get_flags(struct pmbus_data *data, u8 page, unsigned int *flags,
>> +			   bool notify)
>>   
>> -static int __maybe_unused pmbus_get_flags(struct pmbus_data *data, u8 page, unsigned int *flags)
>>   {
>>   	int i, status, ret;
>>   	const struct pmbus_status_category *cat;
>> @@ -2764,6 +2792,10 @@ static int __maybe_unused pmbus_get_flags(struct pmbus_data *data, u8 page, unsi
>>   			if (status & bit->pflag)
>>   				*flags |= bit->rflag;
>>   		}
>> +
>> +		if (notify && status)
>> +			pmbus_notify(data, page, cat->reg, status);
>> +
>>   	}
>>   
>>   	/*
>> @@ -2866,7 +2898,7 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned
>>   	struct i2c_client *client = to_i2c_client(dev->parent);
>>   	struct pmbus_data *data = i2c_get_clientdata(client);
>>   
>> -	return pmbus_get_flags(data, rdev_get_id(rdev), flags);
>> +	return pmbus_get_flags(data, rdev_get_id(rdev), flags, false);
>>   }
>>   
>>   static int pmbus_regulator_get_status(struct regulator_dev *rdev)
>> @@ -3108,10 +3140,14 @@ static irqreturn_t pmbus_fault_handler(int irq, void *pdata)
>>   {
>>   	struct pmbus_data *data = pdata;
>>   	struct i2c_client *client = to_i2c_client(data->dev);
>> -	int i, status;
>> +	int i, status, ret;
>>   
>> -	mutex_lock(&data->update_lock);
>>   	for (i = 0; i < data->info->pages; i++) {
>> +		ret = pmbus_get_flags(data, i, &status, true);
>> +		if (ret)
>> +			return ret;
>> +
>> +		mutex_lock(&data->update_lock);
> 
> You should introduce a locked version of pmbus_get_flags() and call
> that function, and keep the existing locking in place.
> 
I'm not sure if you meant to have pmbus_get_flags that wont use lock?

>>   		status = pmbus_read_status_word(client, i);
>>   		if (status < 0) {
>>   			mutex_unlock(&data->update_lock);
>> @@ -3120,8 +3156,10 @@ static irqreturn_t pmbus_fault_handler(int irq, void *pdata)
>>   
>>   		if (status & ~(PB_STATUS_OFF | PB_STATUS_BUSY | PB_STATUS_POWER_GOOD_N))
>>   			pmbus_clear_fault_page(client, i);
>> +
>> +		mutex_unlock(&data->update_lock);
>>   	}
>> -	mutex_unlock(&data->update_lock);
>> +
> 
> This would add a second empty line (not that it matters because the code
> should not change the locking in the first place).
> 
Will remove the new line
>>   
>>   	return IRQ_HANDLED;
>>   }