Commit 5fa60788 authored by Marek Maslanka's avatar Marek Maslanka Committed by Hans de Goede
Browse files

platform/x86:intel/pmc: Revert "Enable the ACPI PM Timer to be turned off when suspended" 



Commit e86c8186 ("platform/x86:intel/pmc: Enable the ACPI PM Timer to
be turned off when suspended") can cause the suspend process to hang as
the pmcdev->lock in the pmc_core_acpi_pm_timer_suspend_resume might already
be held by the pmc_core_mphy_pg_show or pmc_core_pll_show if the userspace
gets frozen when these functions are being executed.

Also, pmc_core_acpi_pm_timer_suspend_resume must not sleep, as this
function is called indirectly by the tick_freeze function in
kernel/time/tick-common.c, which holds the spinlock.

Revert the changes for now to fix these issues.

Fixes: e86c8186 ("platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended")
Reported-by: default avatarLuca Coelho <luca@coelho.fi>
Closes: https://lore.kernel.org/lkml/40555604c3f4be43bf72e72d5409eaece4be9320.camel@coelho.fi/


Signed-off-by: default avatarMarek Maslanka <mmaslanka@google.com>
Link: https://lore.kernel.org/r/20241012182656.2107178-1-mmaslanka@google.com


Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 2fae3129

drivers/platform/x86/intel/pmc/adl.c

+0 −2
Original line number Diff line number Diff line
@@ -295,8 +295,6 @@ 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,

drivers/platform/x86/intel/pmc/cnp.c

+0 −2
Original line number Diff line number Diff line
@@ -200,8 +200,6 @@ 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,

};

drivers/platform/x86/intel/pmc/core.c

+0 −46
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ 


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/acpi_pmtmr.h>

#include <linux/bitfield.h>

#include <linux/debugfs.h>

#include <linux/delay.h>
@@ -1258,39 +1257,6 @@ 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;



	guard(mutex)(&pmcdev->lock);



	if (!suspend && !pmcdev->enable_acpi_pm_timer_on_resume)

		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;

}



static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)

{

	debugfs_remove_recursive(pmcdev->dbgfs_dir);
@@ -1486,7 +1452,6 @@ static int pmc_core_probe(struct platform_device *pdev) 
	struct pmc_dev *pmcdev;

	const struct x86_cpu_id *cpu_id;

	int (*core_init)(struct pmc_dev *pmcdev);

	const struct pmc_reg_map *map;

	struct pmc *primary_pmc;

	int ret;
@@ -1545,11 +1510,6 @@ static int pmc_core_probe(struct platform_device *pdev) 
	pm_report_max_hw_sleep(FIELD_MAX(SLP_S0_RES_COUNTER_MASK) *

			       pmc_core_adjust_slp_s0_step(primary_pmc, 1));



	map = primary_pmc->map;

	if (map->acpi_pm_tmr_ctl_offset)

		acpi_pmtmr_register_suspend_resume_callback(pmc_core_acpi_pm_timer_suspend_resume,

							 pmcdev);



	device_initialized = true;

	dev_info(&pdev->dev, " initialized\n");
@@ -1559,12 +1519,6 @@ static int pmc_core_probe(struct platform_device *pdev) 
static void pmc_core_remove(struct platform_device *pdev)

{

	struct pmc_dev *pmcdev = platform_get_drvdata(pdev);

	const struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];

	const struct pmc_reg_map *map = pmc->map;



	if (map->acpi_pm_tmr_ctl_offset)

		acpi_pmtmr_unregister_suspend_resume_callback();



	pmc_core_dbgfs_unregister(pmcdev);

	pmc_core_clean_structure(pdev);

}

drivers/platform/x86/intel/pmc/core.h

+0 −8
Original line number Diff line number Diff line
@@ -68,8 +68,6 @@ struct telem_endpoint; 
#define SPT_PMC_LTR_SCC				0x3A0

#define SPT_PMC_LTR_ISH				0x3A4



#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET		0x18FC



/* Sunrise Point: PGD PFET Enable Ack Status Registers */

enum ppfear_regs {

	SPT_PMC_XRAM_PPFEAR0A = 0x590,
@@ -150,8 +148,6 @@ enum ppfear_regs { 
#define SPT_PMC_VRIC1_SLPS0LVEN			BIT(13)

#define SPT_PMC_VRIC1_XTALSDQDIS		BIT(22)



#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE		BIT(1)



/* Cannonlake Power Management Controller register offsets */

#define CNP_PMC_SLPS0_DBG_OFFSET		0x10B4

#define CNP_PMC_PM_CFG_OFFSET			0x1818
@@ -355,8 +351,6 @@ struct pmc_reg_map { 
	const u8  *lpm_reg_index;

	const u32 pson_residency_offset;

	const u32 pson_residency_counter_step;

	const u32 acpi_pm_tmr_ctl_offset;

	const u32 acpi_pm_tmr_disable_bit;

};



/**
@@ -432,8 +426,6 @@ struct pmc_dev { 
	u32 die_c6_offset;

	struct telem_endpoint *punit_ep;

	struct pmc_info *regmap_list;



	bool enable_acpi_pm_timer_on_resume;

};



enum pmc_index {

drivers/platform/x86/intel/pmc/icl.c

+0 −2
Original line number Diff line number Diff line
@@ -46,8 +46,6 @@ const struct pmc_reg_map icl_reg_map = { 
	.ppfear_buckets = ICL_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 = ICL_NUM_IP_IGN_ALLOWED,

	.etr3_offset = ETR3_OFFSET,

};