[v4,2/5] hwmon: (ina3221) Check channel status for alarms attribute read
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Message ID 20181025235122.3240-3-nicoleotsuka@gmail.com
State Superseded
Headers show
Series
  • hwmon: (ina3221) Implement PM runtime to save power
Related show

Commit Message

Nicolin Chen Oct. 25, 2018, 11:51 p.m. UTC
There is nothing critically wrong to read these two attributes
without having a is_enabled() check at this point. But reading
the MASK_ENABLE register would clear the CVRF bit according to
the datasheet. So it'd be safer to fence for disabled channels
in order to add pm runtime feature.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
---
Changelog
v2->v4:
 * N/A
v1->v2:
 * Returned 0 for alert flags instead of -ENODATA

 drivers/hwmon/ina3221.c | 6 ++++++
 1 file changed, 6 insertions(+)

Patch
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diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index d61688f04594..26cdf3342d80 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -200,6 +200,12 @@  static int ina3221_read_curr(struct device *dev, u32 attr,
 		return 0;
 	case hwmon_curr_crit_alarm:
 	case hwmon_curr_max_alarm:
+		/* No actual register read if channel is disabled */
+		if (!ina3221_is_enabled(ina, channel)) {
+			/* Return 0 for alert flags */
+			*val = 0;
+			return 0;
+		}
 		ret = regmap_field_read(ina->fields[reg], &regval);
 		if (ret)
 			return ret;