usb: typec: fusb302: Fix masking of comparator and bc_lvl interrupts

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@vger.kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Ondrej Jirman <megous@megous.com>
Link: https://lore.kernel.org/r/20211108102833.2793803-1-megous@megous.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c
index 7a2a17866a823b36d5e11bce7e31517fd19c1284..72f9001b07921c96c4f3a91937d1e622fb0edafa 100644 (file)
--- 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 *dev, enum typec_cc_status cc)
                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;