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

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Message-ID: <aed487a4-3f7c-55e8-9c84-feaa1c7f583d@roeck-us.net>
Date:   Tue, 7 May 2019 19:03:33 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     "Angus Ainslie (Purism)" <angus@...ea.ca>, angus.ainslie@...i.sm
Cc:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/1] usb: typec: tcpci: Clear the fault status register

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@...ea.ca>
> ---
>   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 ?
What am I missing here ?

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);
>