[PATCH 5.4 06/92] usb: typec: fusb302: Fix masking of comparator and bc_lvl interrupts

From: Greg Kroah-Hartman
Date: Mon Nov 29 2021 - 16:12:44 EST


From: Ondrej Jirman <megous@xxxxxxxxxx>

commit 362468830dd5bea8bf6ad5203b2ea61f8a4e8288 upstream.

The code that enables either BC_LVL or COMP_CHNG interrupt in tcpm_set_cc
wrongly assumes that the interrupt is unmasked by writing 1 to the apropriate
bit in the mask register. In fact, interrupts are enabled when the mask
is 0, so the tcpm_set_cc enables interrupt for COMP_CHNG when it expects
BC_LVL interrupt to be enabled.

This causes inability of the driver to recognize cable unplug events
in host mode (unplug is recognized only via a COMP_CHNG interrupt).

In device mode this bug was masked by simultaneous triggering of the VBUS
change interrupt, because of loss of VBUS when the port peer is providing
power.

Fixes: 48242e30532b ("usb: typec: fusb302: Revert "Resolve fixed power role contract setup"")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Ondrej Jirman <megous@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211108102833.2793803-1-megous@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/typec/tcpm/fusb302.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/usb/typec/tcpm/fusb302.c
+++ b/drivers/usb/typec/tcpm/fusb302.c
@@ -669,25 +669,27 @@ static int tcpm_set_cc(struct tcpc_dev *
ret = fusb302_i2c_mask_write(chip, FUSB_REG_MASK,
FUSB_REG_MASK_BC_LVL |
FUSB_REG_MASK_COMP_CHNG,
- FUSB_REG_MASK_COMP_CHNG);
+ FUSB_REG_MASK_BC_LVL);
if (ret < 0) {
fusb302_log(chip, "cannot set SRC interrupt, ret=%d",
ret);
goto done;
}
chip->intr_comp_chng = true;
+ chip->intr_bc_lvl = false;
break;
case TYPEC_CC_RD:
ret = fusb302_i2c_mask_write(chip, FUSB_REG_MASK,
FUSB_REG_MASK_BC_LVL |
FUSB_REG_MASK_COMP_CHNG,
- FUSB_REG_MASK_BC_LVL);
+ FUSB_REG_MASK_COMP_CHNG);
if (ret < 0) {
fusb302_log(chip, "cannot set SRC interrupt, ret=%d",
ret);
goto done;
}
chip->intr_bc_lvl = true;
+ chip->intr_comp_chng = false;
break;
default:
break;