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

From: Guenter Roeck
Date: Tue Feb 14 2023 - 09:55:06 EST


On 2/14/23 06:11, Naresh Solanki wrote:
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@xxxxxxxxxxxxx>

Notify hwmon events using the pmbus irq handler.

Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
...
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?



__pmbus_get_flags(...)
{
/* no lock acquired here */
}

pmbus_get_flags(...)
{
int ret;

mutex_lock(&data->update_lock);
ret = __pmbus_get_flags(...);
mutex_unlock(&data->update_lock);
return ret;
}

Then call __pmbus_get_flags() from above code.

Guenter

          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;
  }