diff options
| author | Amit Sunil Dhamne <amitsd@google.com> | 2025-08-15 11:31:51 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-17 12:14:50 +0200 |
| commit | cabb6c5f4d9e7f49bdf8c0a13c74bd93ee35f45a (patch) | |
| tree | 9282e7929870181a55a3e40cf51e5d9dcd9de276 | |
| parent | 45eae113dccaf8e502090ecf5b3d9e9b805add6f (diff) | |
usb: typec: maxim_contaminant: disable low power mode when reading comparator values
Low power mode is enabled when reading CC resistance as part of
`max_contaminant_read_resistance_kohm()` and left in that state.
However, it's supposed to work with 1uA current source. To read CC
comparator values current source is changed to 80uA. This causes a storm
of CC interrupts as it (falsely) detects a potential contaminant. To
prevent this, disable low power mode current sourcing before reading
comparator values.
Fixes: 02b332a06397 ("usb: typec: maxim_contaminant: Implement check_contaminant callback")
Cc: stable <stable@kernel.org>
Signed-off-by: Amit Sunil Dhamne <amitsd@google.com>
Reviewed-by: Badhri Jagan Sridharan <badhri@google.com>
Rule: add
Link: https://lore.kernel.org/stable/20250814-fix-upstream-contaminant-v1-1-801ce8089031%40google.com
Link: https://lore.kernel.org/r/20250815-fix-upstream-contaminant-v2-1-6c8d6c3adafb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/typec/tcpm/maxim_contaminant.c | 5 | ||||
| -rw-r--r-- | drivers/usb/typec/tcpm/tcpci_maxim.h | 1 |
2 files changed, 6 insertions, 0 deletions
diff --git a/drivers/usb/typec/tcpm/maxim_contaminant.c b/drivers/usb/typec/tcpm/maxim_contaminant.c index 0cdda06592fd..818cfe226ac7 100644 --- a/drivers/usb/typec/tcpm/maxim_contaminant.c +++ b/drivers/usb/typec/tcpm/maxim_contaminant.c @@ -188,6 +188,11 @@ static int max_contaminant_read_comparators(struct max_tcpci_chip *chip, u8 *ven if (ret < 0) return ret; + /* Disable low power mode */ + ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCLPMODESEL, + FIELD_PREP(CCLPMODESEL, + LOW_POWER_MODE_DISABLE)); + /* Sleep to allow comparators settle */ usleep_range(5000, 6000); ret = regmap_update_bits(regmap, TCPC_TCPC_CTRL, TCPC_TCPC_CTRL_ORIENTATION, PLUG_ORNT_CC1); diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.h b/drivers/usb/typec/tcpm/tcpci_maxim.h index 76270d5c2838..b33540a42a95 100644 --- a/drivers/usb/typec/tcpm/tcpci_maxim.h +++ b/drivers/usb/typec/tcpm/tcpci_maxim.h @@ -21,6 +21,7 @@ #define CCOVPDIS BIT(6) #define SBURPCTRL BIT(5) #define CCLPMODESEL GENMASK(4, 3) +#define LOW_POWER_MODE_DISABLE 0 #define ULTRA_LOW_POWER_MODE 1 #define CCRPCTRL GENMASK(2, 0) #define UA_1_SRC 1 |