From 659cc3d8d5ef246263873fce72c8cadeeed073cc Mon Sep 17 00:00:00 2001 From: Jianing Li Date: Mon, 27 Jul 2026 14:48:25 +0800 Subject: power: supply: max17040: propagate register read errors max17040_get_vcell() and max17040_get_soc() ignore errors returned by regmap_read(). When an I2C transfer fails, the uninitialized register value is converted and reported to userspace as a valid voltage or state of charge. The polling worker can also replace the cached state of charge with the bogus value and emit a spurious change event. Propagate read errors through the power supply get_property callback and keep the last valid cached state of charge when polling fails. Fixes: c6f4a42de60b ("Add MAX17040 Fuel Gauge driver") Cc: stable@vger.kernel.org Signed-off-by: Jianing Li Link: https://patch.msgid.link/20260727064825.948-1-m13940358460@163.com Signed-off-by: Sebastian Reichel --- drivers/power/supply/max17040_battery.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c index e94d53b36aa4..98d34d5f3c80 100644 --- a/drivers/power/supply/max17040_battery.c +++ b/drivers/power/supply/max17040_battery.c @@ -192,8 +192,11 @@ static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell) static int max17040_get_vcell(struct max17040_chip *chip) { u32 vcell; + int ret; - regmap_read(chip->regmap, MAX17040_VCELL, &vcell); + ret = regmap_read(chip->regmap, MAX17040_VCELL, &vcell); + if (ret) + return ret; return max17040_raw_vcell_to_uvolts(chip, vcell); } @@ -201,8 +204,11 @@ static int max17040_get_vcell(struct max17040_chip *chip) static int max17040_get_soc(struct max17040_chip *chip) { u32 soc; + int ret; - regmap_read(chip->regmap, MAX17040_SOC, &soc); + ret = regmap_read(chip->regmap, MAX17040_SOC, &soc); + if (ret) + return ret; return soc >> (chip->quirk_double_soc ? 9 : 8); } @@ -261,7 +267,11 @@ static int max17040_get_of_data(struct max17040_chip *chip) static void max17040_check_changes(struct max17040_chip *chip) { - chip->soc = max17040_get_soc(chip); + int soc; + + soc = max17040_get_soc(chip); + if (soc >= 0) + chip->soc = soc; } static void max17040_queue_work(struct max17040_chip *chip) @@ -396,10 +406,16 @@ static int max17040_get_property(struct power_supply *psy, val->intval = max17040_get_online(chip); break; case POWER_SUPPLY_PROP_VOLTAGE_NOW: - val->intval = max17040_get_vcell(chip); + ret = max17040_get_vcell(chip); + if (ret < 0) + return ret; + val->intval = ret; break; case POWER_SUPPLY_PROP_CAPACITY: - val->intval = max17040_get_soc(chip); + ret = max17040_get_soc(chip); + if (ret < 0) + return ret; + val->intval = ret; break; case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: val->intval = chip->low_soc_alert; -- cgit v1.2.3