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/phy/nuvoton/Kconfig | 12 +++ drivers/phy/nuvoton/Makefile | 3 + drivers/phy/nuvoton/phy-ma35d1-usb2.c | 143 ++++++++++++++++++++++++++++++++++ 3 files changed, 158 insertions(+) create mode 100644 drivers/phy/nuvoton/Kconfig create mode 100644 drivers/phy/nuvoton/Makefile create mode 100644 drivers/phy/nuvoton/phy-ma35d1-usb2.c (limited to 'drivers/phy/nuvoton') diff --git a/drivers/phy/nuvoton/Kconfig b/drivers/phy/nuvoton/Kconfig new file mode 100644 index 000000000..d02cae2db --- /dev/null +++ b/drivers/phy/nuvoton/Kconfig @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# PHY drivers for Nuvoton MA35 platforms +# +config PHY_MA35_USB + tristate "Nuvoton MA35 USB2.0 PHY driver" + depends on ARCH_MA35 || COMPILE_TEST + depends on OF + select GENERIC_PHY + help + Enable this to support the USB2.0 PHY on the Nuvoton MA35 + series SoCs. diff --git a/drivers/phy/nuvoton/Makefile b/drivers/phy/nuvoton/Makefile new file mode 100644 index 000000000..2937e3921 --- /dev/null +++ b/drivers/phy/nuvoton/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_PHY_MA35_USB) += phy-ma35d1-usb2.o diff --git a/drivers/phy/nuvoton/phy-ma35d1-usb2.c b/drivers/phy/nuvoton/phy-ma35d1-usb2.c new file mode 100644 index 000000000..9a459b700 --- /dev/null +++ b/drivers/phy/nuvoton/phy-ma35d1-usb2.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2024 Nuvoton Technology Corp. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* USB PHY Miscellaneous Control Register */ +#define MA35_SYS_REG_USBPMISCR 0x60 +#define PHY0POR BIT(0) /* PHY Power-On Reset Control Bit */ +#define PHY0SUSPEND BIT(1) /* PHY Suspend; 0: suspend, 1: operaion */ +#define PHY0COMN BIT(2) /* PHY Common Block Power-Down Control */ +#define PHY0DEVCKSTB BIT(10) /* PHY 60 MHz UTMI clock stable bit */ + +struct ma35_usb_phy { + struct clk *clk; + struct device *dev; + struct regmap *sysreg; +}; + +static int ma35_usb_phy_power_on(struct phy *phy) +{ + struct ma35_usb_phy *p_phy = phy_get_drvdata(phy); + unsigned int val; + int ret; + + ret = clk_prepare_enable(p_phy->clk); + if (ret < 0) { + dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret); + return ret; + } + + regmap_read(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, &val); + if (val & PHY0SUSPEND) { + /* + * USB PHY0 is in operation mode already + * make sure USB PHY 60 MHz UTMI Interface Clock ready + */ + ret = regmap_read_poll_timeout(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, val, + val & PHY0DEVCKSTB, 10, 1000); + if (ret == 0) + return 0; + } + + /* + * reset USB PHY0. + * wait until USB PHY0 60 MHz UTMI Interface Clock ready + */ + regmap_update_bits(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, 0x7, (PHY0POR | PHY0SUSPEND)); + udelay(20); + + /* make USB PHY0 enter operation mode */ + regmap_update_bits(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, 0x7, PHY0SUSPEND); + + /* make sure USB PHY 60 MHz UTMI Interface Clock ready */ + ret = regmap_read_poll_timeout(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, val, + val & PHY0DEVCKSTB, 10, 1000); + if (ret == -ETIMEDOUT) { + dev_err(p_phy->dev, "Check PHY clock, Timeout: %d\n", ret); + clk_disable_unprepare(p_phy->clk); + return ret; + } + + return 0; +} + +static int ma35_usb_phy_power_off(struct phy *phy) +{ + struct ma35_usb_phy *p_phy = phy_get_drvdata(phy); + + clk_disable_unprepare(p_phy->clk); + return 0; +} + +static const struct phy_ops ma35_usb_phy_ops = { + .power_on = ma35_usb_phy_power_on, + .power_off = ma35_usb_phy_power_off, + .owner = THIS_MODULE, +}; + +static int ma35_usb_phy_probe(struct platform_device *pdev) +{ + struct phy_provider *provider; + struct ma35_usb_phy *p_phy; + struct phy *phy; + + p_phy = devm_kzalloc(&pdev->dev, sizeof(*p_phy), GFP_KERNEL); + if (!p_phy) + return -ENOMEM; + + p_phy->dev = &pdev->dev; + platform_set_drvdata(pdev, p_phy); + + p_phy->sysreg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "nuvoton,sys"); + if (IS_ERR(p_phy->sysreg)) + return dev_err_probe(&pdev->dev, PTR_ERR(p_phy->sysreg), + "Failed to get SYS registers\n"); + + p_phy->clk = of_clk_get(pdev->dev.of_node, 0); + if (IS_ERR(p_phy->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(p_phy->clk), + "failed to find usb_phy clock\n"); + + phy = devm_phy_create(&pdev->dev, NULL, &ma35_usb_phy_ops); + if (IS_ERR(phy)) + return dev_err_probe(&pdev->dev, PTR_ERR(phy), "Failed to create PHY\n"); + + phy_set_drvdata(phy, p_phy); + + provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate); + if (IS_ERR(provider)) + return dev_err_probe(&pdev->dev, PTR_ERR(provider), + "Failed to register PHY provider\n"); + return 0; +} + +static const struct of_device_id ma35_usb_phy_of_match[] = { + { .compatible = "nuvoton,ma35d1-usb2-phy", }, + { }, +}; +MODULE_DEVICE_TABLE(of, ma35_usb_phy_of_match); + +static struct platform_driver ma35_usb_phy_driver = { + .probe = ma35_usb_phy_probe, + .driver = { + .name = "ma35d1-usb2-phy", + .of_match_table = ma35_usb_phy_of_match, + }, +}; +module_platform_driver(ma35_usb_phy_driver); + +MODULE_DESCRIPTION("Nuvoton ma35d1 USB2.0 PHY driver"); +MODULE_AUTHOR("Hui-Ping Chen "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1