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

From: Angus Ainslie
Date: Tue May 07 2019 - 22:50:19 EST

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 ?



+ 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);
+ }