From 0d6526f82c3cdefcca47f73f5fc08dc6f335eac6 Mon Sep 17 00:00:00 2001 From: Tim Chen Date: Mon, 21 Sep 2026 17:37:22 -0700 Subject: sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug alb_break_llc() decides whether to break LLC preference during active load balance. It does so by testing that every runnable fair task on the source rq prefers its LLC: env->src_rq->nr_pref_llc_running == env->src_rq->cfs.h_nr_runnable But the two counters cover different sets. nr_pref_llc_running is updated in account_llc_enqueue()/account_llc_dequeue(), next to cfs_rq->nr_queued, so it follows queued tasks. h_nr_runnable is updated in set_delayed()/ clear_delayed() and drops delay-dequeued tasks. So under DELAY_DEQUEUE, a preferring task that goes to sleep stays counted in nr_pref_llc_running while h_nr_runnable falls. The equality then breaks, alb_break_llc() returns false, and active balance is free to pull a task off its preferred LLC. Active balance only moves runnable tasks, and this is the only LLC check it consults: once the stopper runs, LBF_ACTIVE_LB skips the per-task test in can_migrate_task(). The runnable set is the one we want. Fix it on the counter side. A task should be counted in nr_pref_llc_running exactly while it is both queued on its preferred LLC (pref_llc_queued) and runnable (!sched_delayed). Define that membership once in task_pref_llc_runnable(), and adjust the counter only through pref_llc_running_inc()/pref_llc_running_dec() from the four sites that change either input: account_llc_enqueue(), account_llc_dequeue(), set_delayed() and clear_delayed(). Gating every update on the same predicate keeps the delay, wake and dequeue paths from double-counting or underflowing; see the comments at those sites for the ordering. nr_llc_running and sd->llc_counts are not touched and stay on queued semantics. Fixes: 714059f79ff0 ("sched/cache: Handle moving single tasks to/from their preferred LLC") Closes: https://lore.kernel.org/lkml/20260827135000.735138-1-zhanxusheng@xiaomi.com/ Reported-by: Zhan Xusheng Suggested-by: Chen Yu Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Kayra Cizmeci Cc: # v7.2.x Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com --- drivers/mfd/max77843.c | 217 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 217 insertions(+) create mode 100644 drivers/mfd/max77843.c (limited to 'drivers/mfd/max77843.c') diff --git a/drivers/mfd/max77843.c b/drivers/mfd/max77843.c new file mode 100644 index 000000000..2a48577b1 --- /dev/null +++ b/drivers/mfd/max77843.c @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// MFD core driver for the Maxim MAX77843 +// +// Copyright (C) 2015 Samsung Electronics +// Author: Jaewon Kim +// Author: Beomho Seo + +#include +#include +#include +#include +#include +#include +#include +#include + +static const struct mfd_cell max77843_devs[] = { + { + .name = "max77843-muic", + .of_compatible = "maxim,max77843-muic", + }, { + .name = "max77843-regulator", + .of_compatible = "maxim,max77843-regulator", + }, { + .name = "max77843-charger", + .of_compatible = "maxim,max77843-charger" + }, { + .name = "max77843-fuelgauge", + .of_compatible = "maxim,max77843-fuelgauge", + }, { + .name = "max77843-haptic", + .of_compatible = "maxim,max77843-haptic", + }, +}; + +static const struct regmap_config max77843_charger_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = MAX77843_CHG_REG_END, +}; + +static const struct regmap_config max77843_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = MAX77843_SYS_REG_END, +}; + +static const struct regmap_irq max77843_irqs[] = { + /* TOPSYS interrupts */ + { .reg_offset = 0, .mask = MAX77843_SYS_IRQ_SYSUVLO_INT, }, + { .reg_offset = 0, .mask = MAX77843_SYS_IRQ_SYSOVLO_INT, }, + { .reg_offset = 0, .mask = MAX77843_SYS_IRQ_TSHDN_INT, }, + { .reg_offset = 0, .mask = MAX77843_SYS_IRQ_TM_INT, }, +}; + +static const struct regmap_irq_chip max77843_irq_chip = { + .name = "max77843", + .status_base = MAX77843_SYS_REG_SYSINTSRC, + .mask_base = MAX77843_SYS_REG_SYSINTMASK, + .num_regs = 1, + .irqs = max77843_irqs, + .num_irqs = ARRAY_SIZE(max77843_irqs), +}; + +/* Charger and Charger regulator use same regmap. */ +static int max77843_chg_init(struct max77693_dev *max77843) +{ + int ret; + + max77843->i2c_chg = i2c_new_dummy_device(max77843->i2c->adapter, I2C_ADDR_CHG); + if (IS_ERR(max77843->i2c_chg)) { + dev_err(&max77843->i2c->dev, + "Cannot allocate I2C device for Charger\n"); + return PTR_ERR(max77843->i2c_chg); + } + i2c_set_clientdata(max77843->i2c_chg, max77843); + + max77843->regmap_chg = devm_regmap_init_i2c(max77843->i2c_chg, + &max77843_charger_regmap_config); + if (IS_ERR(max77843->regmap_chg)) { + ret = PTR_ERR(max77843->regmap_chg); + goto err_chg_i2c; + } + + return 0; + +err_chg_i2c: + i2c_unregister_device(max77843->i2c_chg); + + return ret; +} + +static int max77843_probe(struct i2c_client *i2c) +{ + const struct i2c_device_id *id = i2c_client_get_device_id(i2c); + struct max77693_dev *max77843; + unsigned int reg_data; + int ret; + + max77843 = devm_kzalloc(&i2c->dev, sizeof(*max77843), GFP_KERNEL); + if (!max77843) + return -ENOMEM; + + i2c_set_clientdata(i2c, max77843); + max77843->dev = &i2c->dev; + max77843->i2c = i2c; + max77843->irq = i2c->irq; + max77843->type = id->driver_data; + + max77843->regmap = devm_regmap_init_i2c(i2c, + &max77843_regmap_config); + if (IS_ERR(max77843->regmap)) { + dev_err(&i2c->dev, "Failed to allocate topsys register map\n"); + return PTR_ERR(max77843->regmap); + } + + ret = regmap_add_irq_chip(max77843->regmap, max77843->irq, + IRQF_TRIGGER_LOW | IRQF_ONESHOT | IRQF_SHARED, + 0, &max77843_irq_chip, &max77843->irq_data_topsys); + if (ret) { + dev_err(&i2c->dev, "Failed to add TOPSYS IRQ chip\n"); + return ret; + } + + ret = regmap_read(max77843->regmap, + MAX77843_SYS_REG_PMICID, ®_data); + if (ret < 0) { + dev_err(&i2c->dev, "Failed to read PMIC ID\n"); + goto err_pmic_id; + } + dev_info(&i2c->dev, "device ID: 0x%x\n", reg_data); + + ret = max77843_chg_init(max77843); + if (ret) { + dev_err(&i2c->dev, "Failed to init Charger\n"); + goto err_pmic_id; + } + + ret = regmap_update_bits(max77843->regmap, + MAX77843_SYS_REG_INTSRCMASK, + MAX77843_INTSRC_MASK_MASK, + (unsigned int)~MAX77843_INTSRC_MASK_MASK); + if (ret < 0) { + dev_err(&i2c->dev, "Failed to unmask interrupt source\n"); + goto err_pmic_id; + } + + ret = mfd_add_devices(max77843->dev, -1, max77843_devs, + ARRAY_SIZE(max77843_devs), NULL, 0, NULL); + if (ret < 0) { + dev_err(&i2c->dev, "Failed to add mfd device\n"); + goto err_pmic_id; + } + + device_init_wakeup(max77843->dev, true); + + return 0; + +err_pmic_id: + regmap_del_irq_chip(max77843->irq, max77843->irq_data_topsys); + + return ret; +} + +static const struct of_device_id max77843_dt_match[] = { + { .compatible = "maxim,max77843", }, + { }, +}; + +static const struct i2c_device_id max77843_id[] = { + { "max77843", TYPE_MAX77843, }, + { }, +}; + +static int __maybe_unused max77843_suspend(struct device *dev) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct max77693_dev *max77843 = i2c_get_clientdata(i2c); + + disable_irq(max77843->irq); + if (device_may_wakeup(dev)) + enable_irq_wake(max77843->irq); + + return 0; +} + +static int __maybe_unused max77843_resume(struct device *dev) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct max77693_dev *max77843 = i2c_get_clientdata(i2c); + + if (device_may_wakeup(dev)) + disable_irq_wake(max77843->irq); + enable_irq(max77843->irq); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(max77843_pm, max77843_suspend, max77843_resume); + +static struct i2c_driver max77843_i2c_driver = { + .driver = { + .name = "max77843", + .pm = &max77843_pm, + .of_match_table = max77843_dt_match, + .suppress_bind_attrs = true, + }, + .probe = max77843_probe, + .id_table = max77843_id, +}; + +static int __init max77843_i2c_init(void) +{ + return i2c_add_driver(&max77843_i2c_driver); +} +subsys_initcall(max77843_i2c_init); -- cgit v1.3.1