On Wed, Aug 11, 2021 at 10:19:44PM +0000, Chris Packham wrote:
>
> 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.
What a mess. This needs to be documented in the driver, including the
behavior if any of those attributes is written into.
Guenter
> >
> > Guenter
> >
> >> break;
> >> case PMBUS_POUT_OP_WARN_LIMIT:
> >> ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_POUT_MAX);
> >> --
> >> 2.32.0
> >>
