On Wed, Aug 16, 2023 at 02:25:02PM -0300, Fabio Estevam wrote:
> From: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
>
> 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 reset to
> their default values.
>
> This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
> fault-irq, which may cause a kernel hang. Fix this generically by writing
> a one to the corresponding bit-7.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 74e656d6b055 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
> Reported-by: Angus Ainslie (Purism) <angus@xxxxxxxx>
> Closes: https://lore.kernel.org/all/20190508002749.14816-2-angus@xxxxxxxx/
> Reported-by: Christian Bach <christian.bach@xxxxxx>
> Closes: https://lore.kernel.org/regressions/ZR0P278MB07737E5F1D48632897D51AC3EB329@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/t/
> Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> Signed-off-by: Fabio Estevam <festevam@xxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> Changes since v2:
> - Submitted it as a standalone patch.
> - Explain that it may cause a kernel hang.
> - Fixed typos in the commit log. (Guenter)
> - Check the tcpci_write16() return value. (Guenter)
> - Write to TCPC_FAULT_STATUS unconditionally. (Guenter)
> - Added Fixes, Reported-by and Closes tags.
> - CCed stable
>
> drivers/usb/typec/tcpm/tcpci.c | 4 ++++
> include/linux/usb/tcpci.h | 1 +
> 2 files changed, 5 insertions(+)
>
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index fc708c289a73..0ee3e6e29bb1 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -602,6 +602,10 @@ static int tcpci_init(struct tcpc_dev *tcpc)
> if (time_after(jiffies, timeout))
> return -ETIMEDOUT;
>
> + ret = tcpci_write16(tcpci, TCPC_FAULT_STATUS, TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
> + if (ret < 0)
> + return ret;
> +
> /* 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
>
> --
> 2.34.1
>
