On Fri, Jul 2, 2021 at 7:50 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > > The I2C-bus to the XPower AXP288 is shared between the Linux kernel and > the SoCs PUNIT. The PUNIT 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. > > Move / add iosf_mbi_block_punit_i2c_access() calls in / to the XPower > OpRegion code so that the PUNIT semaphore only needs to be taken once > for each OpRegion access. We usually spell "P-Unit" instead of "PUNIT". Otherwise it looks good to me, thanks! Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > drivers/acpi/pmic/intel_pmic_xpower.c | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) > > diff --git a/drivers/acpi/pmic/intel_pmic_xpower.c b/drivers/acpi/pmic/intel_pmic_xpower.c > index a091d5a8392c..644a495a4f13 100644 > --- a/drivers/acpi/pmic/intel_pmic_xpower.c > +++ b/drivers/acpi/pmic/intel_pmic_xpower.c > @@ -178,15 +178,17 @@ static int intel_xpower_pmic_update_power(struct regmap *regmap, int reg, > { > int data, ret; > > - /* GPIO1 LDO regulator needs special handling */ > - if (reg == XPOWER_GPI1_CTRL) > - return regmap_update_bits(regmap, reg, GPI1_LDO_MASK, > - on ? GPI1_LDO_ON : GPI1_LDO_OFF); > - > ret = iosf_mbi_block_punit_i2c_access(); > if (ret) > return ret; > > + /* GPIO1 LDO regulator needs special handling */ > + if (reg == XPOWER_GPI1_CTRL) { > + ret = regmap_update_bits(regmap, reg, GPI1_LDO_MASK, > + on ? GPI1_LDO_ON : GPI1_LDO_OFF); > + goto out; > + } > + > if (regmap_read(regmap, reg, &data)) { > ret = -EIO; > goto out; > @@ -218,6 +220,10 @@ static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg) > int ret, adc_ts_pin_ctrl; > u8 buf[2]; > > + ret = iosf_mbi_block_punit_i2c_access(); > + if (ret) > + return ret; > + > /* > * The current-source used for the battery temp-sensor (TS) is shared > * with the GPADC. For proper fuel-gauge and charger operation the TS > @@ -231,14 +237,14 @@ static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg) > */ > ret = regmap_read(regmap, AXP288_ADC_TS_PIN_CTRL, &adc_ts_pin_ctrl); > if (ret) > - return ret; > + goto out; > > if (adc_ts_pin_ctrl & AXP288_ADC_TS_CURRENT_ON_OFF_MASK) { > ret = regmap_update_bits(regmap, AXP288_ADC_TS_PIN_CTRL, > AXP288_ADC_TS_CURRENT_ON_OFF_MASK, > AXP288_ADC_TS_CURRENT_ON_ONDEMAND); > if (ret) > - return ret; > + goto out; > > /* Wait a bit after switching the current-source */ > usleep_range(6000, 10000); > @@ -254,6 +260,9 @@ static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg) > AXP288_ADC_TS_CURRENT_ON); > } > > +out: > + iosf_mbi_unblock_punit_i2c_access(); > + > return ret; > } > > -- > 2.31.1 > -- With Best Regards, Andy Shevchenko