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SubjectRe: [PATCH v2 3/4] usb: typec: tcpci: clear the fault status bit
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On 5/4/23 07:27, Marco Felsch wrote:
> On 23-05-04, Guenter Roeck wrote:
>> On 5/4/23 06:46, Marco Felsch wrote:
>>> According the "USB Type-C Port Controller Interface Specification v2.0"
>>> the TCPC sets the fault status register bit-7
>>> (AllRegistersResetToDefault) once the registers have been reseted to
>>
>> cleared ? set ?
>
> Sry. I don't get this.
>

instead of "reseted" which isn't really a word.

>>> their default values.
>>>
>>> This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
>>> fault-irq. Fix this gernally by writing a one to the correspondig
>>
>> generically ?
>
> Sure, thanks.
>
>> corresponding
>
> Of course!
>
>>> bit-7.
>>>
>>> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
>>> ---
>>> drivers/usb/typec/tcpm/tcpci.c | 5 +++++
>>> include/linux/usb/tcpci.h | 1 +
>>> 2 files changed, 6 insertions(+)
>>>
>>> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
>>> index 8da23240afbe..15632d023e4c 100644
>>> --- a/drivers/usb/typec/tcpm/tcpci.c
>>> +++ b/drivers/usb/typec/tcpm/tcpci.c
>>> @@ -602,6 +602,11 @@ static int tcpci_init(struct tcpc_dev *tcpc)
>>> if (time_after(jiffies, timeout))
>>> return -ETIMEDOUT;
>>> + regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &reg);
>>
>> Needs error check.
>
> I will add this.
>
>> Also, I am not sure if this is the correct place for this code. The alert
>> status is cleared after vendor initialization. Should the same be done
>> here ?
>
> According the spec the bit must be cleared before the TCPC_ALERT is
> cleared. Of course the vendor-init can (re-)trigger the bit, therefore
> we should move behind the vendor init and right before the TCPC_ALERT
> clear.
>
>> Also, why not just write the bit unconditionally, similar
>> to TCPC_ALERT ?
>
> Thought about this too.. I will change it in the v3.
>
> Thanks for the feedback,
> Marco
>
>>
>> Thanks,
>> Guenter
>>
>>> + if (reg & TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT)
>>> + tcpci_write16(tcpci, TCPC_FAULT_STATUS,
>>> + TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
>>> +
>>> /* Handle vendor init */
>>> if (tcpci->data->init) {
>>> ret = tcpci->data->init(tcpci, tcpci->data);
>>> diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
>>> index 85e95a3251d3..83376473ac76 100644
>>> --- a/include/linux/usb/tcpci.h
>>> +++ b/include/linux/usb/tcpci.h
>>> @@ -103,6 +103,7 @@
>>> #define TCPC_POWER_STATUS_SINKING_VBUS BIT(0)
>>> #define TCPC_FAULT_STATUS 0x1f
>>> +#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
>>> #define TCPC_ALERT_EXTENDED 0x21
>>>
>>
>>

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