Re: [PATCH v3 2/2] usb: typec: tcpci: set ALERT_MASK register after devm_request_threaded_irq()

[Francesco Dolcini <francesco@dolcini.it>]

On Tue, Dec 17, 2024 at 05:12:08PM +0800, Xu Yang wrote:
> With edge irq support, the ALERT event may be missed currently. The reason
> is that ALERT_MASK register is written before devm_request_threaded_irq().
> If ALERT event happens in this time gap, it will be missed and ALERT line
> will not recover to high level. However, we don't meet this issue with
> level irq. To avoid the issue, this will set ALERT_MASK register after
> devm_request_threaded_irq() return.
> 
> Fixes: 77e85107a771 ("usb: typec: tcpci: support edge irq")
> Cc: stable@vger.kernel.org
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> 
> ---
> Changes in v3:
>  - remove set_alert_mask flag
> Changes in v2:
>  - new patch
> ---
>  drivers/usb/typec/tcpm/tcpci.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index db42f4bf3632..48762508cc86 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -700,7 +700,7 @@ static int tcpci_init(struct tcpc_dev *tcpc)
>  
>  	tcpci->alert_mask = reg;
>  
> -	return tcpci_write16(tcpci, TCPC_ALERT_MASK, reg);
> +	return 0;

Should we set the alert mask to 0 at the beginning of tcpci_init() ?

Just wondering if some bind/unbind or module reload use case would need
it.

Francesco