diff mbox series

[v3,4/6] hwmon: (pmbus/core) clear faults after setting smbalert mask

Message ID 20241024-tps25990-v3-4-b6a6e9d4b506@baylibre.com (mailing list archive)
State Changes Requested
Headers show
Series hwmon: pmbus: add tps25990 efuse support | expand

Commit Message

Jerome Brunet Oct. 24, 2024, 6:10 p.m. UTC
pmbus_write_smbalert_mask() ignores the errors if the chip can't set
smbalert mask the standard way. It is not necessarily a problem for the irq
support if the chip is otherwise properly setup but it may leave an
uncleared fault behind.

pmbus_core will pick the fault on the next register_check(). The register
check will fails regardless of the actual register support by the chip.

This leads to missing attributes or debugfs entries for chips that should
provide them.

We cannot rely on register_check() as PMBUS_SMBALERT_MASK may be read-only.

Unconditionally clear the page fault after setting PMBUS_SMBALERT_MASK to
avoid the problem.

Suggested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 221819ca4c36 ("hwmon: (pmbus/core) Add interrupt support")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/hwmon/pmbus/pmbus_core.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Guenter Roeck Nov. 1, 2024, 3:10 p.m. UTC | #1
On Thu, Oct 24, 2024 at 08:10:38PM +0200, Jerome Brunet wrote:
> pmbus_write_smbalert_mask() ignores the errors if the chip can't set
> smbalert mask the standard way. It is not necessarily a problem for the irq
> support if the chip is otherwise properly setup but it may leave an
> uncleared fault behind.
> 
> pmbus_core will pick the fault on the next register_check(). The register
> check will fails regardless of the actual register support by the chip.
> 
> This leads to missing attributes or debugfs entries for chips that should
> provide them.
> 
> We cannot rely on register_check() as PMBUS_SMBALERT_MASK may be read-only.
> 
> Unconditionally clear the page fault after setting PMBUS_SMBALERT_MASK to
> avoid the problem.
> 
> Suggested-by: Guenter Roeck <linux@roeck-us.net>
> Fixes: 221819ca4c36 ("hwmon: (pmbus/core) Add interrupt support")
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> ---
>  drivers/hwmon/pmbus/pmbus_core.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index ce697ca03de01c0e5a352f8f6b72671137721868..a0a397d571caa1a6620ef095f9cf63d94e8bda1d 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -3346,7 +3346,12 @@ static int pmbus_regulator_notify(struct pmbus_data *data, int page, int event)
>  
>  static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val)
>  {
> -	return _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
> +	int ret;
> +
> +	ret = _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
> +	pmbus_clear_fault_page(client, -1);

Why -1 and not page ?

Guenter
Jerome Brunet Nov. 4, 2024, 8:28 a.m. UTC | #2
On Fri 01 Nov 2024 at 08:10, Guenter Roeck <linux@roeck-us.net> wrote:

> On Thu, Oct 24, 2024 at 08:10:38PM +0200, Jerome Brunet wrote:
>> pmbus_write_smbalert_mask() ignores the errors if the chip can't set
>> smbalert mask the standard way. It is not necessarily a problem for the irq
>> support if the chip is otherwise properly setup but it may leave an
>> uncleared fault behind.
>> 
>> pmbus_core will pick the fault on the next register_check(). The register
>> check will fails regardless of the actual register support by the chip.
>> 
>> This leads to missing attributes or debugfs entries for chips that should
>> provide them.
>> 
>> We cannot rely on register_check() as PMBUS_SMBALERT_MASK may be read-only.
>> 
>> Unconditionally clear the page fault after setting PMBUS_SMBALERT_MASK to
>> avoid the problem.
>> 
>> Suggested-by: Guenter Roeck <linux@roeck-us.net>
>> Fixes: 221819ca4c36 ("hwmon: (pmbus/core) Add interrupt support")
>> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
>> ---
>>  drivers/hwmon/pmbus/pmbus_core.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
>> index ce697ca03de01c0e5a352f8f6b72671137721868..a0a397d571caa1a6620ef095f9cf63d94e8bda1d 100644
>> --- a/drivers/hwmon/pmbus/pmbus_core.c
>> +++ b/drivers/hwmon/pmbus/pmbus_core.c
>> @@ -3346,7 +3346,12 @@ static int pmbus_regulator_notify(struct pmbus_data *data, int page, int event)
>>  
>>  static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val)
>>  {
>> -	return _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
>> +	int ret;
>> +
>> +	ret = _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
>> +	pmbus_clear_fault_page(client, -1);
>
> Why -1 and not page ?

The idea was to clear the fault on the page we are on, basically just skipping
setting the page again.

I'll change to 'page'

>
> Guenter
Guenter Roeck Nov. 4, 2024, 1:51 p.m. UTC | #3
On 11/4/24 00:28, Jerome Brunet wrote:
> On Fri 01 Nov 2024 at 08:10, Guenter Roeck <linux@roeck-us.net> wrote:
> 
>> On Thu, Oct 24, 2024 at 08:10:38PM +0200, Jerome Brunet wrote:
>>> pmbus_write_smbalert_mask() ignores the errors if the chip can't set
>>> smbalert mask the standard way. It is not necessarily a problem for the irq
>>> support if the chip is otherwise properly setup but it may leave an
>>> uncleared fault behind.
>>>
>>> pmbus_core will pick the fault on the next register_check(). The register
>>> check will fails regardless of the actual register support by the chip.
>>>
>>> This leads to missing attributes or debugfs entries for chips that should
>>> provide them.
>>>
>>> We cannot rely on register_check() as PMBUS_SMBALERT_MASK may be read-only.
>>>
>>> Unconditionally clear the page fault after setting PMBUS_SMBALERT_MASK to
>>> avoid the problem.
>>>
>>> Suggested-by: Guenter Roeck <linux@roeck-us.net>
>>> Fixes: 221819ca4c36 ("hwmon: (pmbus/core) Add interrupt support")
>>> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
>>> ---
>>>   drivers/hwmon/pmbus/pmbus_core.c | 7 ++++++-
>>>   1 file changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
>>> index ce697ca03de01c0e5a352f8f6b72671137721868..a0a397d571caa1a6620ef095f9cf63d94e8bda1d 100644
>>> --- a/drivers/hwmon/pmbus/pmbus_core.c
>>> +++ b/drivers/hwmon/pmbus/pmbus_core.c
>>> @@ -3346,7 +3346,12 @@ static int pmbus_regulator_notify(struct pmbus_data *data, int page, int event)
>>>   
>>>   static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val)
>>>   {
>>> -	return _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
>>> +	int ret;
>>> +
>>> +	ret = _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
>>> +	pmbus_clear_fault_page(client, -1);
>>
>> Why -1 and not page ?
> 
> The idea was to clear the fault on the page we are on, basically just skipping
> setting the page again.
> 
> I'll change to 'page'
> 
Or just add a comment explaining the '-1'.

Thanks,
Guenter
diff mbox series

Patch

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index ce697ca03de01c0e5a352f8f6b72671137721868..a0a397d571caa1a6620ef095f9cf63d94e8bda1d 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -3346,7 +3346,12 @@  static int pmbus_regulator_notify(struct pmbus_data *data, int page, int event)
 
 static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val)
 {
-	return _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
+	int ret;
+
+	ret = _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
+	pmbus_clear_fault_page(client, -1);
+
+	return ret;
 }
 
 static irqreturn_t pmbus_fault_handler(int irq, void *pdata)