[PATCH] hwmon: (pmbus) Fix page count auto-detection.

[PATCH] hwmon: (pmbus) Fix page count auto-detection.

[Dmitry Bazhenov]

Devices with compatible="pmbus" field have zero initial page count,
and pmbus_clear_faults() being called before the page count auto-
detection does not actually clear faults because it depends on the
page count. Non-cleared faults in its turn may fail the subsequent
page count auto-detection.

This patch fixes this problem by calling pmbus_clear_fault_page()
for currently set page and calling pmbus_clear_faults() after the
page count was detected.

Signed-off-by: Dmitry Bazhenov <bazhenov.dn@gmail.com>
---
 drivers/hwmon/pmbus/pmbus.c      | 2 ++
 drivers/hwmon/pmbus/pmbus_core.c | 5 ++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/pmbus.c b/drivers/hwmon/pmbus/pmbus.c
index 7718e58dbda5..7688dab32f6e 100644
--- a/drivers/hwmon/pmbus/pmbus.c
+++ b/drivers/hwmon/pmbus/pmbus.c
@@ -118,6 +118,8 @@ static int pmbus_identify(struct i2c_client *client,
 		} else {
 			info->pages = 1;
 		}
+
+		pmbus_clear_faults(client);
 	}
 
 	if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE)) {
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 82c3754e21e3..2e2b5851139c 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -2015,7 +2015,10 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
 	if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK))
 		client->flags |= I2C_CLIENT_PEC;
 
-	pmbus_clear_faults(client);
+	if (data->info->pages)
+		pmbus_clear_faults(client);
+	else
+		pmbus_clear_fault_page(client, -1);
 
 	if (info->identify) {
 		ret = (*info->identify)(client, info);
-- 
2.17.1

Re: [PATCH] hwmon: (pmbus) Fix page count auto-detection.

[Guenter Roeck]

On Mon, Oct 15, 2018 at 02:21:22PM +0500, Dmitry Bazhenov wrote:
> Devices with compatible="pmbus" field have zero initial page count,
> and pmbus_clear_faults() being called before the page count auto-
> detection does not actually clear faults because it depends on the
> page count. Non-cleared faults in its turn may fail the subsequent
> page count auto-detection.
> 
> This patch fixes this problem by calling pmbus_clear_fault_page()
> for currently set page and calling pmbus_clear_faults() after the
> page count was detected.
> 
> Signed-off-by: Dmitry Bazhenov <bazhenov.dn@gmail.com>

Applied.

Thanks,
Guenter

> ---
>  drivers/hwmon/pmbus/pmbus.c      | 2 ++
>  drivers/hwmon/pmbus/pmbus_core.c | 5 ++++-
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/pmbus/pmbus.c b/drivers/hwmon/pmbus/pmbus.c
> index 7718e58dbda5..7688dab32f6e 100644
> --- a/drivers/hwmon/pmbus/pmbus.c
> +++ b/drivers/hwmon/pmbus/pmbus.c
> @@ -118,6 +118,8 @@ static int pmbus_identify(struct i2c_client *client,
>  		} else {
>  			info->pages = 1;
>  		}
> +
> +		pmbus_clear_faults(client);
>  	}
>  
>  	if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE)) {
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index 82c3754e21e3..2e2b5851139c 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -2015,7 +2015,10 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
>  	if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK))
>  		client->flags |= I2C_CLIENT_PEC;
>  
> -	pmbus_clear_faults(client);
> +	if (data->info->pages)
> +		pmbus_clear_faults(client);
> +	else
> +		pmbus_clear_fault_page(client, -1);
>  
>  	if (info->identify) {
>  		ret = (*info->identify)(client, info);