diff mbox series

hwmon: (pmbus) Fix vout margin caching

Message ID 20220816144414.2358974-1-vincent.whitchurch@axis.com (mailing list archive)
State Accepted
Headers show
Series hwmon: (pmbus) Fix vout margin caching | expand

Commit Message

Vincent Whitchurch Aug. 16, 2022, 2:44 p.m. UTC
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@axis.com>
---
 drivers/hwmon/pmbus/pmbus_core.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Comments

Guenter Roeck Aug. 17, 2022, 3:32 p.m. UTC | #1
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@axis.com>

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;
diff mbox series

Patch

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;