On Tue, Aug 16, 2022 at 04:44:14PM +0200, Vincent Whitchurch wrote:
> The code currently uses a zero margin to mean not cached, but this
> results in the cache being bypassed if the (low) margin is set to zero,
> leading to lots of unnecessary SMBus transactions in that case. Use a
> negative value instead.
>
> Fixes: 07fb76273db89d93 ("hwmon: (pmbus) Introduce and use cached vout margins")
> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
Applied.
Thanks,
Guenter
> ---
> drivers/hwmon/pmbus/pmbus_core.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index f10bac8860fc..d06b04543fd8 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -2861,7 +2861,7 @@ static int pmbus_regulator_get_low_margin(struct i2c_client *client, int page)
> .data = -1,
> };
>
> - if (!data->vout_low[page]) {
> + if (data->vout_low[page] < 0) {
> if (pmbus_check_word_register(client, page, PMBUS_MFR_VOUT_MIN))
> s.data = _pmbus_read_word_data(client, page, 0xff,
> PMBUS_MFR_VOUT_MIN);
> @@ -2887,7 +2887,7 @@ static int pmbus_regulator_get_high_margin(struct i2c_client *client, int page)
> .data = -1,
> };
>
> - if (!data->vout_high[page]) {
> + if (data->vout_high[page] < 0) {
> if (pmbus_check_word_register(client, page, PMBUS_MFR_VOUT_MAX))
> s.data = _pmbus_read_word_data(client, page, 0xff,
> PMBUS_MFR_VOUT_MAX);
> @@ -3320,6 +3320,7 @@ int pmbus_do_probe(struct i2c_client *client, struct pmbus_driver_info *info)
> struct pmbus_data *data;
> size_t groups_num = 0;
> int ret;
> + int i;
> char *name;
>
> if (!info)
> @@ -3353,6 +3354,11 @@ int pmbus_do_probe(struct i2c_client *client, struct pmbus_driver_info *info)
> data->currpage = -1;
> data->currphase = -1;
>
> + for (i = 0; i < ARRAY_SIZE(data->vout_low); i++) {
> + data->vout_low[i] = -1;
> + data->vout_high[i] = -1;
> + }
> +
> ret = pmbus_init_common(client, data, info);
> if (ret < 0)
> return ret;
