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

[Guenter Roeck]

On 5/7/19 7:49 PM, Angus Ainslie wrote:
> 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>
> > > ---
> > > Â drivers/usb/typec/tcpm/tcpci.c | 11 +++++++++++
> > > Â 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)
> > > ÂÂÂÂÂ else if (status & TCPC_ALERT_TX_FAILED)
> > > ÂÂÂÂÂÂÂÂÂ tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_FAILED);
> > > Â +ÂÂÂ 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 ?

There is a TCPC_ALERT_FAULT mask bit, so I would think so.
Can you dump register contents in the irq function and at the end of
tcpci_init() ?

Thanks,
Guenter

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