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| author | Hans de Goede <hdegoede@redhat.com> | 2021-08-01 15:31:00 +0200 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2021-08-05 18:54:52 +0200 |
| commit | f17bda7f655fa5ede982a487b8f6d732bbe1959a (patch) | |
| tree | 19fc35ec602391eb6b5c70798d0461d4ae8c3c1a /drivers/power | |
| parent | caa534c3ba40c6e8352b42cbbbca9ba481814ac8 (diff) | |
| download | linux-f17bda7f655fa5ede982a487b8f6d732bbe1959a.tar.bz2 | |
power: supply: axp288_fuel_gauge: Drop retry logic from fuel_gauge_reg_readb()
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. This semaphore is automatically taken by the
I2C-bus-driver.
The retry on -EBUSY logic in fuel_gauge_reg_readb() likely was added to
deal with the I2C-bus-drive returning -EBUSY when it failed to take the
semaphore, but this really should never happen. The semaphore code even
has a WARN_ON(ret) to log a kernel backtrace if this does somehow happen,
when this happens something is seriously wrong and the system typically
freezes soon afterwards.
TL;DR: the regmap_read() should never fail with -EBUSY so the retries
are unnecessary.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Diffstat (limited to 'drivers/power')
| -rw-r--r-- | drivers/power/supply/axp288_fuel_gauge.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/drivers/power/supply/axp288_fuel_gauge.c b/drivers/power/supply/axp288_fuel_gauge.c index 796153caf5e0..d58a1f81fcea 100644 --- a/drivers/power/supply/axp288_fuel_gauge.c +++ b/drivers/power/supply/axp288_fuel_gauge.c @@ -76,7 +76,6 @@ #define FG_LOW_CAP_CRIT_THR 4 /* 4 perc */ #define FG_LOW_CAP_SHDN_THR 0 /* 0 perc */ -#define NR_RETRY_CNT 3 #define DEV_NAME "axp288_fuel_gauge" /* 1.1mV per LSB expressed in uV */ @@ -132,15 +131,10 @@ static enum power_supply_property fuel_gauge_props[] = { static int fuel_gauge_reg_readb(struct axp288_fg_info *info, int reg) { - int ret, i; unsigned int val; + int ret; - for (i = 0; i < NR_RETRY_CNT; i++) { - ret = regmap_read(info->regmap, reg, &val); - if (ret != -EBUSY) - break; - } - + ret = regmap_read(info->regmap, reg, &val); if (ret < 0) { dev_err(&info->pdev->dev, "Error reading reg 0x%02x err: %d\n", reg, ret); return ret; |