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usb: typec: tcpci: don't handle vSafe0V event if it's not enabled
authorXu Yang <xu.yang_2@nxp.com>
Sun, 26 Sep 2021 10:14:15 +0000 (18:14 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 5 Oct 2021 11:46:46 +0000 (13:46 +0200)
commit05300871c0e21c288bd5c30ac6f9b1da6ddeed22
treebf9fb596c987a1a6472445300974da4634feeb28
parentb87d8d0d4c43c29ccdc57d15b2ebc1df886a34b4
usb: typec: tcpci: don't handle vSafe0V event if it's not enabled

USB TCPCI Spec, 4.4.3 Mask Registers:
"A masked register will still indicate in the ALERT register, but shall
not set the Alert# pin low."

Thus, the Extended Status will still indicate in ALERT register if vSafe0V
is detected by TCPC even though being masked. In current code, howerer,
this event will not be handled in detection time. Rather it will be
handled when next ALERT event coming(CC evnet, PD event, etc).

Tcpm might transition to a wrong state in this situation. Thus, the vSafe0V
event should not be handled when it's masked.

Fixes: 766c485b86ef ("usb: typec: tcpci: Add support to report vSafe0V")
cc: <stable@vger.kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20210926101415.3775058-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/typec/tcpm/tcpci.c