Re: [PATCH 2/2] hwmon: (pmbus/bpa-rs600) Add workaround for incorrect Pin max

From: Chris Packham
Date: Wed Aug 11 2021 - 18:19:50 EST



On 12/08/21 7:53 am, Guenter Roeck wrote:
> On Wed, Aug 11, 2021 at 04:17:38PM +1200, Chris Packham wrote:
>> BPD-RS600 modules running firmware v5.70 misreport the MFR_PIN_MAX.
>> The indicate a maximum of 1640W instead of 700W. Detect the invalid
>> reading and return a sensible value instead.
>>
>> Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/hwmon/pmbus/bpa-rs600.c | 21 ++++++++++++++++++++-
>> 1 file changed, 20 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/hwmon/pmbus/bpa-rs600.c b/drivers/hwmon/pmbus/bpa-rs600.c
>> index d495faa89799..f4baed9ce8a4 100644
>> --- a/drivers/hwmon/pmbus/bpa-rs600.c
>> +++ b/drivers/hwmon/pmbus/bpa-rs600.c
>> @@ -65,6 +65,24 @@ static int bpa_rs600_read_vin(struct i2c_client *client)
>> return ret;
>> }
>>
>> +/*
>> + * The firmware on some BPD-RS600 models incorrectly reports 1640W
>> + * for MFR_PIN_MAX. Deal with this by returning a sensible value.
>> + */
>> +static int bpa_rs600_read_pin_max(struct i2c_client *client)
>> +{
>> + int ret;
>> +
>> + ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_PIN_MAX);
>> + if (ret < 0)
>> + return ret;
>> +
>> + if (ret == 0x0b34)
>> + return 0x095e;
> The comments from the descriotion need to be here.
will update
> Thanks,
> Guenter
>
>> +
>> + return ret;
>> +}
>> +
>> static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int phase, int reg)
>> {
>> int ret;
>> @@ -92,7 +110,8 @@ static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int pha
>> ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_IOUT_MAX);
>> break;
>> case PMBUS_PIN_OP_WARN_LIMIT:
>> - ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_PIN_MAX);
>> + case PMBUS_MFR_PIN_MAX:
>> + ret = bpa_rs600_read_pin_max(client);
> So the idea is to return the same value for PMBUS_PIN_OP_WARN_LIMIT
> (max_alarm) and PMBUS_MFR_PIN_MAX (rated_max) ? That doesn't really
> make sense. The meaning of those limits is distinctly different.
For the BPA-RS600/BPD-RS600 these appear to be treated the same.
>
> Guenter
>
>> break;
>> case PMBUS_POUT_OP_WARN_LIMIT:
>> ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_POUT_MAX);
>> --
>> 2.32.0
>>