diff mbox series

[v2,08/10] power: supply: axp288_fuel_gauge: Refresh all registers in one go

Message ID 20210730095607.57541-9-hdegoede@redhat.com
State New
Headers show
Series power: supply: axp288_fuel_gauge: Reduce number of register accesses + cleanups | expand

Commit Message

Hans de Goede July 30, 2021, 9:56 a.m. UTC 
From: Andrejus Basovas <cpp@gcc.lt>

The I2C-bus to the XPower AXP288 is shared between the Linux kernel and
the SoCs P-Unit. The P-Unit has a semaphore which the kernel must "lock"
before it may use the bus and while the kernel holds the semaphore the CPU
and GPU power-states must not be changed otherwise the system will freeze.

This is a complex process, which is quite expensive. This is all done by
iosf_mbi_block_punit_i2c_access(). To ensure that no unguarded I2C-bus
accesses happen, iosf_mbi_block_punit_i2c_access() gets called by the
I2C-bus-driver for every I2C transfer. Because this is so expensive it
is allowed to call iosf_mbi_block_punit_i2c_access() in a nested
fashion, so that higher-level code which does multiple I2C-transfers can
call it once for a group of transfers, turning the calls done by the
I2C-bus-driver into no-ops.

Userspace power-supply API users typically will read all provided
properties in one go, refreshing the last read values when
power_supply_changed() is called by the driver and/or periodically
(e.g. every 2 minutes).

The reading of all properties in one go causes the P-Unit semaphore
to quickly be taken and released multiple times in a row. Certain
PMIC registers like AXP20X_FG_RES are even used in multiple properties
so they get read multiple times, leading to a P-Unit take + release
each time the register is read.

As already mentioned the taking of the P-Unit semaphore is a quite
expensive operation and it has also been reported that the
"hammering" of the P-Unit semaphore done by the axp288_fuel_gauge
driver can even cause stability issues with the system as a whole.

Switch over to a scheme where the axp288_fuel_gauge driver keeps
a local copy of all the registers which it uses for properties
and make it only refresh its copy of the registers if the values
are older then 1 minute; or when a fuel-gauge interrupt has
triggered since the last read.

This not only reduces the amount of reads, it also makes the code
do all the reads in one go, rather then reading specific registers
based on which property is being queried. This allows calling
iosf_mbi_block_punit_i2c_access() once before doing all the reads,
so that we now only take the P-Unit semaphore once per update.

Tested-by: Andrejus Basovas <cpp@gcc.lt>
Signed-off-by: Andrejus Basovas <cpp@gcc.lt>
Co-developed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
- Add a "depends on X86" to Kconfig since the iosf_mbi functions are X86 only
  (the AXP288 PMIC is only used on X86 devices)
---
 drivers/power/supply/Kconfig             |   2 +-
 drivers/power/supply/axp288_fuel_gauge.c | 201 ++++++++++++-----------
 2 files changed, 106 insertions(+), 97 deletions(-)

Comments

kernel test robot July 30, 2021, 1:39 p.m. UTC | #1 
Hi Hans,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on power-supply/for-next]
[also build test ERROR on v5.14-rc3 next-20210729]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Hans-de-Goede/power-supply-axp288_fuel_gauge-Reduce-number-of-register-accesses-cleanups/20210730-175716
base:   https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git for-next
config: i386-randconfig-a005-20210730 (attached as .config)
compiler: gcc-10 (Ubuntu 10.3.0-1ubuntu1~20.04) 10.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/1ff192ccce54fdfce899447999a60a195537460c
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Hans-de-Goede/power-supply-axp288_fuel_gauge-Reduce-number-of-register-accesses-cleanups/20210730-175716
        git checkout 1ff192ccce54fdfce899447999a60a195537460c
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/power/supply/axp288_fuel_gauge.c: In function 'fuel_gauge_update_registers':
>> drivers/power/supply/axp288_fuel_gauge.c:219:8: error: implicit declaration of function 'iosf_mbi_block_punit_i2c_access' [-Werror=implicit-function-declaration]
     219 |  ret = iosf_mbi_block_punit_i2c_access();
         |        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/power/supply/axp288_fuel_gauge.c:268:2: error: implicit declaration of function 'iosf_mbi_unblock_punit_i2c_access' [-Werror=implicit-function-declaration]
     268 |  iosf_mbi_unblock_punit_i2c_access();
         |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/iosf_mbi_block_punit_i2c_access +219 drivers/power/supply/axp288_fuel_gauge.c

   209	
   210	static int fuel_gauge_update_registers(struct axp288_fg_info *info)
   211	{
   212		int ret;
   213	
   214		if (info->valid && time_before(jiffies, info->last_updated + AXP288_REG_UPDATE_INTERVAL))
   215			return 0;
   216	
   217		dev_dbg(info->dev, "Fuel Gauge updating register values...\n");
   218	
 > 219		ret = iosf_mbi_block_punit_i2c_access();
   220		if (ret < 0)
   221			return ret;
   222	
   223		ret = fuel_gauge_reg_readb(info, AXP20X_PWR_INPUT_STATUS);
   224		if (ret < 0)
   225			goto out;
   226		info->pwr_stat = ret;
   227	
   228		ret = fuel_gauge_reg_readb(info, AXP20X_FG_RES);
   229		if (ret < 0)
   230			goto out;
   231		info->fg_res = ret;
   232	
   233		ret = iio_read_channel_raw(info->iio_channel[BAT_VOLT], &info->bat_volt);
   234		if (ret < 0)
   235			goto out;
   236	
   237		if (info->pwr_stat & PS_STAT_BAT_CHRG_DIR) {
   238			info->d_curr = 0;
   239			ret = iio_read_channel_raw(info->iio_channel[BAT_CHRG_CURR], &info->c_curr);
   240			if (ret < 0)
   241				goto out;
   242		} else {
   243			info->c_curr = 0;
   244			ret = iio_read_channel_raw(info->iio_channel[BAT_D_CURR], &info->d_curr);
   245			if (ret < 0)
   246				goto out;
   247		}
   248	
   249		ret = fuel_gauge_read_12bit_word(info, AXP288_FG_OCVH_REG);
   250		if (ret < 0)
   251			goto out;
   252		info->ocv = ret;
   253	
   254		ret = fuel_gauge_read_15bit_word(info, AXP288_FG_CC_MTR1_REG);
   255		if (ret < 0)
   256			goto out;
   257		info->fg_cc_mtr1 = ret;
   258	
   259		ret = fuel_gauge_read_15bit_word(info, AXP288_FG_DES_CAP1_REG);
   260		if (ret < 0)
   261			goto out;
   262		info->fg_des_cap1 = ret;
   263	
   264		info->last_updated = jiffies;
   265		info->valid = 1;
   266		ret = 0;
   267	out:
 > 268		iosf_mbi_unblock_punit_i2c_access();
   269		return ret;
   270	}
   271	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Hans de Goede Aug. 1, 2021, 11:23 a.m. UTC | #2 
Hi,

On 7/30/21 6:14 PM, kernel test robot wrote:
> Hi Hans,

> 

> Thank you for the patch! Yet something to improve:

> 

> [auto build test ERROR on power-supply/for-next]

> [also build test ERROR on v5.14-rc3 next-20210729]

> [If your patch is applied to the wrong git tree, kindly drop us a note.

> And when submitting patch, we suggest to use '--base' as documented in

> https://git-scm.com/docs/git-format-patch]

> 

> url:    https://github.com/0day-ci/linux/commits/Hans-de-Goede/power-supply-axp288_fuel_gauge-Reduce-number-of-register-accesses-cleanups/20210730-175716

> base:   https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git for-next

> config: x86_64-buildonly-randconfig-r001-20210730 (attached as .config)

> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 4f71f59bf3d9914188a11d0c41bedbb339d36ff5)

> reproduce (this is a W=1 build):

>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross

>         chmod +x ~/bin/make.cross

>         # https://github.com/0day-ci/linux/commit/1ff192ccce54fdfce899447999a60a195537460c

>         git remote add linux-review https://github.com/0day-ci/linux

>         git fetch --no-tags linux-review Hans-de-Goede/power-supply-axp288_fuel_gauge-Reduce-number-of-register-accesses-cleanups/20210730-175716

>         git checkout 1ff192ccce54fdfce899447999a60a195537460c

>         # save the attached .config to linux build tree

>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

> 

> If you fix the issue, kindly add following tag as appropriate

> Reported-by: kernel test robot <lkp@intel.com>

> 

> All errors (new ones prefixed by >>):

> 

>>> drivers/power/supply/axp288_fuel_gauge.c:219:8: error: implicit declaration of function 'iosf_mbi_block_punit_i2c_access' [-Werror,-Wimplicit-function-declaration]

>            ret = iosf_mbi_block_punit_i2c_access();

>                  ^

>>> drivers/power/supply/axp288_fuel_gauge.c:268:2: error: implicit declaration of function 'iosf_mbi_unblock_punit_i2c_access' [-Werror,-Wimplicit-function-declaration]

>            iosf_mbi_unblock_punit_i2c_access();

>            ^

>    drivers/power/supply/axp288_fuel_gauge.c:268:2: note: did you mean 'iosf_mbi_block_punit_i2c_access'?

>    drivers/power/supply/axp288_fuel_gauge.c:219:8: note: 'iosf_mbi_block_punit_i2c_access' declared here

>            ret = iosf_mbi_block_punit_i2c_access();

>                  ^

>    2 errors generated.


Ugh, so I guess that it is possible to build a x86 kernel without iosf_mbi support
enabled. Given how the I2C bus to PMIC is special on devices with an AXP288 PMIC
and special attention must be made to coordinate accesses with the SoC-s
P-Unit, allowing building of the AXP288 code without IOSF_MBi makes little sense
(this will lead to a very unreliable kernel build) so I'll do a v3 changing the new
depends on from X86 to IOSF_MBI.

Sorry about all the churn because of this Kconfig depends issue.

Regards,

Hans
diff mbox series

Patch

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 11f5368e810e..56e29d4247c5 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -358,7 +358,7 @@  config AXP288_CHARGER
 
 config AXP288_FUEL_GAUGE
 	tristate "X-Powers AXP288 Fuel Gauge"
-	depends on MFD_AXP20X && IIO
+	depends on MFD_AXP20X && IIO && X86
 	help
 	  Say yes here to have support for X-Power power management IC (PMIC)
 	  Fuel Gauge. The device provides battery statistics and status
diff --git a/drivers/power/supply/axp288_fuel_gauge.c b/drivers/power/supply/axp288_fuel_gauge.c
index 8011628d3704..8db8ab0827e4 100644
--- a/drivers/power/supply/axp288_fuel_gauge.c
+++ b/drivers/power/supply/axp288_fuel_gauge.c
@@ -2,7 +2,8 @@ 
 /*
  * axp288_fuel_gauge.c - Xpower AXP288 PMIC Fuel Gauge Driver
  *
- * Copyright (C) 2016-2017 Hans de Goede <hdegoede@redhat.com>
+ * Copyright (C) 2020-2021 Andrejus Basovas <xxx@yyy.tld>
+ * Copyright (C) 2016-2021 Hans de Goede <hdegoede@redhat.com>
  * Copyright (C) 2014 Intel Corporation
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -20,6 +21,7 @@ 
 #include <linux/power_supply.h>
 #include <linux/iio/consumer.h>
 #include <asm/unaligned.h>
+#include <asm/iosf_mbi.h>
 
 #define PS_STAT_VBUS_TRIGGER			(1 << 0)
 #define PS_STAT_BAT_CHRG_DIR			(1 << 2)
@@ -84,6 +86,7 @@ 
 #define PROP_VOLT(a)				((a) * 1000)
 #define PROP_CURR(a)				((a) * 1000)
 
+#define AXP288_REG_UPDATE_INTERVAL		(60 * HZ)
 #define AXP288_FG_INTR_NUM			6
 enum {
 	QWBTU_IRQ = 0,
@@ -114,6 +117,18 @@  struct axp288_fg_info {
 	int pwr_op;
 	int low_cap;
 	struct dentry *debug_file;
+
+	char valid;                 /* zero until following fields are valid */
+	unsigned long last_updated; /* in jiffies */
+
+	int pwr_stat;
+	int fg_res;
+	int bat_volt;
+	int d_curr;
+	int c_curr;
+	int ocv;
+	int fg_cc_mtr1;
+	int fg_des_cap1;
 };
 
 static enum power_supply_property fuel_gauge_props[] = {
@@ -192,25 +207,78 @@  static int fuel_gauge_read_12bit_word(struct axp288_fg_info *info, int reg)
 	return (buf[0] << 4) | ((buf[1] >> 4) & 0x0f);
 }
 
-static void fuel_gauge_get_status(struct axp288_fg_info *info)
+static int fuel_gauge_update_registers(struct axp288_fg_info *info)
 {
-	int pwr_stat, fg_res, curr, ret;
+	int ret;
 
-	pwr_stat = fuel_gauge_reg_readb(info, AXP20X_PWR_INPUT_STATUS);
-	if (pwr_stat < 0) {
-		dev_err(info->dev, "PWR STAT read failed: %d\n", pwr_stat);
-		return;
+	if (info->valid && time_before(jiffies, info->last_updated + AXP288_REG_UPDATE_INTERVAL))
+		return 0;
+
+	dev_dbg(info->dev, "Fuel Gauge updating register values...\n");
+
+	ret = iosf_mbi_block_punit_i2c_access();
+	if (ret < 0)
+		return ret;
+
+	ret = fuel_gauge_reg_readb(info, AXP20X_PWR_INPUT_STATUS);
+	if (ret < 0)
+		goto out;
+	info->pwr_stat = ret;
+
+	ret = fuel_gauge_reg_readb(info, AXP20X_FG_RES);
+	if (ret < 0)
+		goto out;
+	info->fg_res = ret;
+
+	ret = iio_read_channel_raw(info->iio_channel[BAT_VOLT], &info->bat_volt);
+	if (ret < 0)
+		goto out;
+
+	if (info->pwr_stat & PS_STAT_BAT_CHRG_DIR) {
+		info->d_curr = 0;
+		ret = iio_read_channel_raw(info->iio_channel[BAT_CHRG_CURR], &info->c_curr);
+		if (ret < 0)
+			goto out;
+	} else {
+		info->c_curr = 0;
+		ret = iio_read_channel_raw(info->iio_channel[BAT_D_CURR], &info->d_curr);
+		if (ret < 0)
+			goto out;
 	}
 
+	ret = fuel_gauge_read_12bit_word(info, AXP288_FG_OCVH_REG);
+	if (ret < 0)
+		goto out;
+	info->ocv = ret;
+
+	ret = fuel_gauge_read_15bit_word(info, AXP288_FG_CC_MTR1_REG);
+	if (ret < 0)
+		goto out;
+	info->fg_cc_mtr1 = ret;
+
+	ret = fuel_gauge_read_15bit_word(info, AXP288_FG_DES_CAP1_REG);
+	if (ret < 0)
+		goto out;
+	info->fg_des_cap1 = ret;
+
+	info->last_updated = jiffies;
+	info->valid = 1;
+	ret = 0;
+out:
+	iosf_mbi_unblock_punit_i2c_access();
+	return ret;
+}
+
+static void fuel_gauge_get_status(struct axp288_fg_info *info)
+{
+	int pwr_stat = info->pwr_stat;
+	int fg_res = info->fg_res;
+	int curr = info->d_curr;
+
 	/* Report full if Vbus is valid and the reported capacity is 100% */
 	if (!(pwr_stat & PS_STAT_VBUS_VALID))
 		goto not_full;
 
-	fg_res = fuel_gauge_reg_readb(info, AXP20X_FG_RES);
-	if (fg_res < 0) {
-		dev_err(info->dev, "FG RES read failed: %d\n", fg_res);
-		return;
-	}
 	if (!(fg_res & FG_REP_CAP_VALID))
 		goto not_full;
 
@@ -228,11 +296,6 @@  static void fuel_gauge_get_status(struct axp288_fg_info *info)
 	if (fg_res < 90 || (pwr_stat & PS_STAT_BAT_CHRG_DIR))
 		goto not_full;
 
-	ret = iio_read_channel_raw(info->iio_channel[BAT_D_CURR], &curr);
-	if (ret < 0) {
-		dev_err(info->dev, "FG get current failed: %d\n", ret);
-		return;
-	}
 	if (curr == 0) {
 		info->status = POWER_SUPPLY_STATUS_FULL;
 		return;
@@ -245,61 +308,16 @@  static void fuel_gauge_get_status(struct axp288_fg_info *info)
 		info->status = POWER_SUPPLY_STATUS_DISCHARGING;
 }
 
-static int fuel_gauge_get_vbatt(struct axp288_fg_info *info, int *vbatt)
-{
-	int ret = 0, raw_val;
-
-	ret = iio_read_channel_raw(info->iio_channel[BAT_VOLT], &raw_val);
-	if (ret < 0)
-		goto vbatt_read_fail;
-
-	*vbatt = VOLTAGE_FROM_ADC(raw_val);
-vbatt_read_fail:
-	return ret;
-}
-
-static int fuel_gauge_get_current(struct axp288_fg_info *info, int *cur)
-{
-	int ret, discharge;
-
-	/* First check discharge current, so that we do only 1 read on bat. */
-	ret = iio_read_channel_raw(info->iio_channel[BAT_D_CURR], &discharge);
-	if (ret < 0)
-		return ret;
-
-	if (discharge > 0) {
-		*cur = -1 * discharge;
-		return 0;
-	}
-
-	return iio_read_channel_raw(info->iio_channel[BAT_CHRG_CURR], cur);
-}
-
-static int fuel_gauge_get_vocv(struct axp288_fg_info *info, int *vocv)
-{
-	int ret;
-
-	ret = fuel_gauge_read_12bit_word(info, AXP288_FG_OCVH_REG);
-	if (ret >= 0)
-		*vocv = VOLTAGE_FROM_ADC(ret);
-
-	return ret;
-}
-
 static int fuel_gauge_battery_health(struct axp288_fg_info *info)
 {
-	int ret, vocv, health = POWER_SUPPLY_HEALTH_UNKNOWN;
-
-	ret = fuel_gauge_get_vocv(info, &vocv);
-	if (ret < 0)
-		goto health_read_fail;
+	int vocv = VOLTAGE_FROM_ADC(info->ocv);
+	int health = POWER_SUPPLY_HEALTH_UNKNOWN;
 
 	if (vocv > info->max_volt)
 		health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 	else
 		health = POWER_SUPPLY_HEALTH_GOOD;
 
-health_read_fail:
 	return health;
 }
 
@@ -308,9 +326,14 @@  static int fuel_gauge_get_property(struct power_supply *ps,
 		union power_supply_propval *val)
 {
 	struct axp288_fg_info *info = power_supply_get_drvdata(ps);
-	int ret = 0, value;
+	int ret, value;
 
 	mutex_lock(&info->lock);
+
+	ret = fuel_gauge_update_registers(info);
+	if (ret < 0)
+		goto out;
+
 	switch (prop) {
 	case POWER_SUPPLY_PROP_STATUS:
 		fuel_gauge_get_status(info);
@@ -320,21 +343,19 @@  static int fuel_gauge_get_property(struct power_supply *ps,
 		val->intval = fuel_gauge_battery_health(info);
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
-		ret = fuel_gauge_get_vbatt(info, &value);
-		if (ret < 0)
-			goto fuel_gauge_read_err;
+		value = VOLTAGE_FROM_ADC(info->bat_volt);
 		val->intval = PROP_VOLT(value);
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_OCV:
-		ret = fuel_gauge_get_vocv(info, &value);
-		if (ret < 0)
-			goto fuel_gauge_read_err;
+		value = VOLTAGE_FROM_ADC(info->ocv);
 		val->intval = PROP_VOLT(value);
 		break;
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
-		ret = fuel_gauge_get_current(info, &value);
-		if (ret < 0)
-			goto fuel_gauge_read_err;
+		if (info->d_curr > 0)
+			value = -1 * info->d_curr;
+		else
+			value = info->c_curr;
+
 		val->intval = PROP_CURR(value);
 		break;
 	case POWER_SUPPLY_PROP_PRESENT:
@@ -344,13 +365,9 @@  static int fuel_gauge_get_property(struct power_supply *ps,
 			val->intval = 0;
 		break;
 	case POWER_SUPPLY_PROP_CAPACITY:
-		ret = fuel_gauge_reg_readb(info, AXP20X_FG_RES);
-		if (ret < 0)
-			goto fuel_gauge_read_err;
-
-		if (!(ret & FG_REP_CAP_VALID))
+		if (!(info->fg_res & FG_REP_CAP_VALID))
 			dev_err(info->dev, "capacity measurement not valid\n");
-		val->intval = (ret & FG_REP_CAP_VAL_MASK);
+		val->intval = (info->fg_res & FG_REP_CAP_VAL_MASK);
 		break;
 	case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
 		val->intval = (info->low_cap & 0x0f);
@@ -359,31 +376,19 @@  static int fuel_gauge_get_property(struct power_supply *ps,
 		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_NOW:
-		ret = fuel_gauge_read_15bit_word(info, AXP288_FG_CC_MTR1_REG);
-		if (ret < 0)
-			goto fuel_gauge_read_err;
-
-		val->intval = ret * FG_DES_CAP_RES_LSB;
+		val->intval = info->fg_cc_mtr1 * FG_DES_CAP_RES_LSB;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_FULL:
-		ret = fuel_gauge_read_15bit_word(info, AXP288_FG_DES_CAP1_REG);
-		if (ret < 0)
-			goto fuel_gauge_read_err;
-
-		val->intval = ret * FG_DES_CAP_RES_LSB;
+		val->intval = info->fg_des_cap1 * FG_DES_CAP_RES_LSB;
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 		val->intval = PROP_VOLT(info->max_volt);
 		break;
 	default:
-		mutex_unlock(&info->lock);
-		return -EINVAL;
+		ret = -EINVAL;
 	}
 
-	mutex_unlock(&info->lock);
-	return 0;
-
-fuel_gauge_read_err:
+out:
 	mutex_unlock(&info->lock);
 	return ret;
 }
@@ -472,6 +477,8 @@  static irqreturn_t fuel_gauge_thread_handler(int irq, void *dev)
 		dev_warn(info->dev, "Spurious Interrupt!!!\n");
 	}
 
+	info->valid = 0; /* Force updating of the cached registers */
+
 	power_supply_changed(info->bat);
 	return IRQ_HANDLED;
 }
@@ -480,6 +487,7 @@  static void fuel_gauge_external_power_changed(struct power_supply *psy)
 {
 	struct axp288_fg_info *info = power_supply_get_drvdata(psy);
 
+	info->valid = 0; /* Force updating of the cached registers */
 	power_supply_changed(info->bat);
 }
 
@@ -637,6 +645,7 @@  static int axp288_fuel_gauge_probe(struct platform_device *pdev)
 	info->regmap = axp20x->regmap;
 	info->regmap_irqc = axp20x->regmap_irqc;
 	info->status = POWER_SUPPLY_STATUS_UNKNOWN;
+	info->valid = 0;
 
 	platform_set_drvdata(pdev, info);