On Mon, 12 Aug 2024, Marek Maslanka wrote: > Allow to disable ACPI PM Timer on suspend and enable on resume. A > disabled timer helps optimise power consumption when the system is > suspended. On resume the timer is only reactivated if it was activated > prior to suspend, so unless the ACPI PM timer is enabled in the BIOS, > this won't change anything. > > The ACPI PM timer is used by Intel's iTCO/wdat_wdt watchdog to drive the > watchdog, so it doesn't need to run during suspend. > > Signed-off-by: Marek Maslanka <mmaslanka@xxxxxxxxxx> > > --- > Changes in v5: > - Use renamed acpi_pmtmr_register_suspend_resume_callback instead of > acpi_pm_register_suspend_resume_callback > - Link to v4: https://lore.kernel.org/lkml/20240809131343.1173369-2-mmaslanka@xxxxxxxxxx/ > --- > --- > drivers/platform/x86/intel/pmc/adl.c | 2 ++ > drivers/platform/x86/intel/pmc/cnp.c | 2 ++ > drivers/platform/x86/intel/pmc/core.c | 49 +++++++++++++++++++++++++++ > drivers/platform/x86/intel/pmc/core.h | 8 +++++ > drivers/platform/x86/intel/pmc/icl.c | 2 ++ > drivers/platform/x86/intel/pmc/mtl.c | 2 ++ > drivers/platform/x86/intel/pmc/spt.c | 2 ++ > drivers/platform/x86/intel/pmc/tgl.c | 2 ++ > 8 files changed, 69 insertions(+) > > diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c > index e7878558fd909..9d9c07f44ff61 100644 > --- a/drivers/platform/x86/intel/pmc/adl.c > +++ b/drivers/platform/x86/intel/pmc/adl.c > @@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = { > .ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES, > .pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET, > .pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT, > + .acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET, > + .acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE, > .ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED, > .lpm_num_modes = ADL_LPM_NUM_MODES, > .lpm_num_maps = ADL_LPM_NUM_MAPS, > diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c > index dd72974bf71e2..513c02670c5aa 100644 > --- a/drivers/platform/x86/intel/pmc/cnp.c > +++ b/drivers/platform/x86/intel/pmc/cnp.c > @@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = { > .ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES, > .pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET, > .pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT, > + .acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET, > + .acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE, > .ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED, > .etr3_offset = ETR3_OFFSET, > }; > diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c > index 10c96c1a850af..d65e3e77ec2ca 100644 > --- a/drivers/platform/x86/intel/pmc/core.c > +++ b/drivers/platform/x86/intel/pmc/core.c > @@ -11,6 +11,7 @@ > > #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > > +#include <linux/acpi_pmtmr.h> > #include <linux/bitfield.h> > #include <linux/debugfs.h> > #include <linux/delay.h> > @@ -1171,6 +1172,42 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev) > return val == 1; > } > > +/** > + * Enable or disable ACPI PM Timer > + * > + * This function is intended to be a callback for ACPI PM suspend/resume event. > + * The ACPI PM Timer is enabled on resume only if it was enabled during suspend. > + */ > +static void pmc_core_acpi_pm_timer_suspend_resume(void *data, bool suspend) > +{ > + struct pmc_dev *pmcdev = data; > + struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN]; > + const struct pmc_reg_map *map = pmc->map; > + bool enabled; > + u32 reg; > + > + if (!map->acpi_pm_tmr_ctl_offset) > + return; > + > + mutex_lock(&pmcdev->lock); > + > + if (!suspend && !pmcdev->enable_acpi_pm_timer_on_resume) { > + mutex_unlock(&pmcdev->lock); Use guard() in this function so you don't need to manually unlock. -- i. > + return; > + } > + > + reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset); > + enabled = !(reg & map->acpi_pm_tmr_disable_bit); > + if (suspend) > + reg |= map->acpi_pm_tmr_disable_bit; > + else > + reg &= ~map->acpi_pm_tmr_disable_bit; > + pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg); > + > + pmcdev->enable_acpi_pm_timer_on_resume = suspend && enabled; > + > + mutex_unlock(&pmcdev->lock); > +}
