On 3/16/22 13:03, Brandon Wyman wrote:
On Sun, Mar 13, 2022 at 11:36 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
On 3/11/22 10:10, Brandon Wyman wrote:
Add a clear_faults write-only debugfs entry for the ibm-cffps device
driver.
Certain IBM power supplies require clearing some latched faults in order
to indicate that the fault has indeed been observed/noticed.
That is insufficient, sorry. Please provide the affected power supplies as
well as the affected faults, and confirm that the problem still exists
in v5.17-rc6 or later kernels - or, more specifically, in any kernel which
includes commit 35f165f08950 ("hwmon: (pmbus) Clear pmbus fault/warning
bits after read").
Thanks,
Guenter
Sorry for the delay in responding. I did some testing with commit
35f165f08950. I could not get that code to send the CLEAR_FAULTS
command to the power supplies.
I can update the commit message to be more specific about which power
supplies need this CLEAR_FAULTS sent, and which faults. It is observed
with the 1600W power supplies (2B1E model). The faults that latch are
the VIN_UV and INPUT faults in the STATUS_WORD. The corresponding
STATUS_INPUT fault bits are VIN_UV_FAULT and Unit is Off.
The point is that the respective fault bits should be reset when the
corresponding alarm attributes are read. This isn't about executing
a CLEAR_FAULTS command, but about selectively resetting fault bits
while ensuring that faults are reported at least once. Executing
CLEAR_FAULTS is a big hammer.
With the patch I pointed to in place, input (and other) faults should
be reset after the corresponding alarm attributes are read, assuming
that the condition no longer exists. If that does not happen, we should
fix the problem instead of deploying the big hammer.
Thanks,
Guenter
Signed-off-by: Brandon Wyman <bjwyman@xxxxxxxxx>
---
V1 -> V2: Explain why this change is needed
drivers/hwmon/pmbus/ibm-cffps.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c
index e3294a1a54bb..3f02dde02a4b 100644
--- a/drivers/hwmon/pmbus/ibm-cffps.c
+++ b/drivers/hwmon/pmbus/ibm-cffps.c
@@ -67,6 +67,7 @@ enum {
CFFPS_DEBUGFS_CCIN,
CFFPS_DEBUGFS_FW,
CFFPS_DEBUGFS_ON_OFF_CONFIG,
+ CFFPS_DEBUGFS_CLEAR_FAULTS,
CFFPS_DEBUGFS_NUM_ENTRIES
};
@@ -274,6 +275,13 @@ static ssize_t ibm_cffps_debugfs_write(struct file *file,
if (rc)
return rc;
+ rc = 1;
+ break;
+ case CFFPS_DEBUGFS_CLEAR_FAULTS:
+ rc = i2c_smbus_write_byte(psu->client, PMBUS_CLEAR_FAULTS);
+ if (rc < 0)
+ return rc;
+
rc = 1;
break;
default:
@@ -607,6 +615,9 @@ static int ibm_cffps_probe(struct i2c_client *client)
debugfs_create_file("on_off_config", 0644, ibm_cffps_dir,
&psu->debugfs_entries[CFFPS_DEBUGFS_ON_OFF_CONFIG],
&ibm_cffps_fops);
+ debugfs_create_file("clear_faults", 0200, ibm_cffps_dir,
+ &psu->debugfs_entries[CFFPS_DEBUGFS_CLEAR_FAULTS],
+ &ibm_cffps_fops);
return 0;
}
