Re: [PATCH v2 1/1] usb: typec: tcpci: Clear the fault status register

[Angus Ainslie]

On 2019-05-07 20:03, Guenter Roeck wrote:
> On 5/7/19 5:27 PM, Angus Ainslie (Purism) wrote:
> > If the fault status register doesn't get cleared then
> > the ptn5110 interrupt gets stuck on. As the fault register gets
> > set everytime the ptn5110 powers on the interrupt is always stuck.
> >
> > Fixes: fault status register stuck
> > Signed-off-by: Angus Ainslie (Purism) <angus@xxxxxxxx>
> > ---
> >   drivers/usb/typec/tcpm/tcpci.c | 11 +++++++++++
> >   1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpci.c 
> > b/drivers/usb/typec/tcpm/tcpci.c
> > index c1f7073a56de..a5746657b190 100644
> > --- a/drivers/usb/typec/tcpm/tcpci.c
> > +++ b/drivers/usb/typec/tcpm/tcpci.c
> > @@ -463,6 +463,17 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
> >   	else if (status & TCPC_ALERT_TX_FAILED)
> >   		tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_FAILED);
> >   +	if (status & TCPC_ALERT_FAULT) {
>
> Wait - the driver doesn't set TCPC_ALERT_FAULT in the alert mask
> register. How can the chip report it if fault alerts are not enabled ?

Well that I didn't check. But I know this code gets executed so 
something must be turning it on.

Also if I don't clear it I get an unlimited number of interrupts.

> What am I missing here ?

Can the power on fault be masked ?

Angus

> Thanks,
> Guenter
>
> > +		u16 fault_status;
> > +
> > +		tcpci_read16(tcpci, TCPC_FAULT_STATUS, &fault_status);
> > +
> > +		dev_warn(tcpci->dev, "FAULT ALERT status 0x%x\n", fault_status);
> > +
> > +		/* clear the fault status */
> > +		tcpci_write16(tcpci, TCPC_FAULT_STATUS, fault_status);
> > +	}
> > +
> >   	return IRQ_HANDLED;
> >   }
> >   EXPORT_SYMBOL_GPL(tcpci_irq);