Messages in this thread | | | Date | Thu, 10 Feb 2022 06:44:07 -0800 | From | Guenter Roeck <> | Subject | Re: [PATCH] hwmon: (pmbus) Clear pmbus fault/warning bits before read |
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On 2/10/22 04:41, Vikash Chandola wrote: > pmbus fault and warning bits are not cleared by itself once fault/warning > condition is not valid anymore. As per pmbus datasheet faults must be > cleared by user. > Modify hwmon behavior to clear latched status bytes if any bit in status > register is high prior to returning fresh data to userspace. If > fault/warning conditions are still applicable fault/warning bits will be > set and we will get updated data in second read. > > Hwmon behavior is changed here. Now sysfs reads will reflect latest > values from pmbus slave, not latched values. > In case a transient warning/fault has happened in the past, it will no > longer be reported to userspace. >
NACK.
Reporting that information is exactly the point of the current code. We _do_ want to report at least once that a problem occurred in the past, and only clear the warning flag(s) afterwards.
Guenter
> Signed-off-by: Vikash Chandola <vikash.chandola@linux.intel.com> > --- > drivers/hwmon/pmbus/pmbus_core.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c > index 776ee2237be2..1cc82d644079 100644 > --- a/drivers/hwmon/pmbus/pmbus_core.c > +++ b/drivers/hwmon/pmbus/pmbus_core.c > @@ -577,6 +577,15 @@ static int pmbus_get_status(struct i2c_client *client, int page, int reg) > break; > default: > status = _pmbus_read_byte_data(client, page, reg); > + if (status > 0) { > + /* > + * Status greater than 0 could mean that there was a fault/warning. > + * Clear faults and do a second read to make sure we are not getting > + * stale values. > + */ > + pmbus_clear_fault_page(client, page); > + status = _pmbus_read_byte_data(client, page, reg); > + } > break; > } > if (status < 0)
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