diff options
| author | Vishnu Razdan <vrazdan@openai.com> | 2026-08-24 23:58:00 -0700 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2026-09-09 18:16:34 -0700 |
| commit | 6d760f8b41aed74de4402440e4db663d261478bd (patch) | |
| tree | 33aa33d65b89efccaf23bd80f9e04168d9d2879f | |
| parent | 286b175bb03893949f24621f356abd9d20368b0a (diff) | |
hwmon: (pmbus) Clear generic status alarms with CLEAR_FAULTS
Some hwmon alarms fall back to STATUS_WORD summary bits when no
individual limit alarm is available. On PMBus 1.2 and newer devices,
pmbus_get_boolean() acknowledges these alarms with the same byte-data
write used for detailed status registers. For example, PB_STATUS_INPUT
is 0x2000, so it is truncated to zero when passed to
_pmbus_write_byte_data(). The resulting write cannot acknowledge the
input alarm.
PMBus 1.3 Part II, sections 10.2.4 and 10.2.5, excludes ordinary
STATUS_BYTE and STATUS_WORD summary bits from individual clearing.
Their summary bits clear when the underlying status bits clear, so
changing this to a word-data write would not fix the generic input
alarm either.
Use the existing page CLEAR_FAULTS path for generic STATUS_WORD
alarms, including devices whose status accessor uses STATUS_BYTE.
Keep individual byte writes for detailed status registers on PMBus
1.2 and newer devices. As with the existing older-device fallback,
CLEAR_FAULTS can clear other latched status; an active condition can
reassert its status.
Fixes: 35f165f08950 ("hwmon: (pmbus) Clear pmbus fault/warning bits after read")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Vishnu Razdan <vrazdan@openai.com>
Link: https://patch.msgid.link/20260824-vrazdan-pmbus-status-word-b4-v1-1-2606ecd0c029@openai.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
| -rw-r--r-- | drivers/hwmon/pmbus/pmbus_core.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index 806c9a4913bb..5f69c1420b4e 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -1275,7 +1275,9 @@ static int pmbus_get_boolean(struct i2c_client *client, struct pmbus_boolean *b, regval = status & mask; if (regval) { - if (data->revision >= PMBUS_REV_12) { + /* Generic STATUS_WORD alarms are not individually clearable. */ + if (data->revision >= PMBUS_REV_12 && + reg != PMBUS_STATUS_WORD) { ret = _pmbus_write_byte_data(client, page, reg, regval); if (ret) return ret; |