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/input/touchscreen/htcpen.c | 243 +++++++++++++++++++++++++++++++++++++ 1 file changed, 243 insertions(+) create mode 100644 drivers/input/touchscreen/htcpen.c (limited to 'drivers/input/touchscreen/htcpen.c') diff --git a/drivers/input/touchscreen/htcpen.c b/drivers/input/touchscreen/htcpen.c new file mode 100644 index 000000000..056ba7608 --- /dev/null +++ b/drivers/input/touchscreen/htcpen.c @@ -0,0 +1,243 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * HTC Shift touchscreen driver + * + * Copyright (C) 2008 Pau Oliva Fora + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +MODULE_AUTHOR("Pau Oliva Fora "); +MODULE_DESCRIPTION("HTC Shift touchscreen driver"); +MODULE_LICENSE("GPL"); + +#define HTCPEN_PORT_IRQ_CLEAR 0x068 +#define HTCPEN_PORT_INIT 0x06c +#define HTCPEN_PORT_INDEX 0x0250 +#define HTCPEN_PORT_DATA 0x0251 +#define HTCPEN_IRQ 3 + +#define DEVICE_ENABLE 0xa2 +#define DEVICE_DISABLE 0xa3 + +#define X_INDEX 3 +#define Y_INDEX 5 +#define TOUCH_INDEX 0xb +#define LSB_XY_INDEX 0xc +#define X_AXIS_MAX 2040 +#define Y_AXIS_MAX 2040 + +static bool invert_x; +module_param(invert_x, bool, 0644); +MODULE_PARM_DESC(invert_x, "If set, X axis is inverted"); +static bool invert_y; +module_param(invert_y, bool, 0644); +MODULE_PARM_DESC(invert_y, "If set, Y axis is inverted"); + +static irqreturn_t htcpen_interrupt(int irq, void *handle) +{ + struct input_dev *htcpen_dev = handle; + unsigned short x, y, xy; + + /* 0 = press; 1 = release */ + outb_p(TOUCH_INDEX, HTCPEN_PORT_INDEX); + + if (inb_p(HTCPEN_PORT_DATA)) { + input_report_key(htcpen_dev, BTN_TOUCH, 0); + } else { + outb_p(X_INDEX, HTCPEN_PORT_INDEX); + x = inb_p(HTCPEN_PORT_DATA); + + outb_p(Y_INDEX, HTCPEN_PORT_INDEX); + y = inb_p(HTCPEN_PORT_DATA); + + outb_p(LSB_XY_INDEX, HTCPEN_PORT_INDEX); + xy = inb_p(HTCPEN_PORT_DATA); + + /* get high resolution value of X and Y using LSB */ + x = X_AXIS_MAX - ((x * 8) + ((xy >> 4) & 0xf)); + y = (y * 8) + (xy & 0xf); + if (invert_x) + x = X_AXIS_MAX - x; + if (invert_y) + y = Y_AXIS_MAX - y; + + if (x != X_AXIS_MAX && x != 0) { + input_report_key(htcpen_dev, BTN_TOUCH, 1); + input_report_abs(htcpen_dev, ABS_X, x); + input_report_abs(htcpen_dev, ABS_Y, y); + } + } + + input_sync(htcpen_dev); + + inb_p(HTCPEN_PORT_IRQ_CLEAR); + + return IRQ_HANDLED; +} + +static int htcpen_open(struct input_dev *dev) +{ + outb_p(DEVICE_ENABLE, HTCPEN_PORT_INIT); + + return 0; +} + +static void htcpen_close(struct input_dev *dev) +{ + outb_p(DEVICE_DISABLE, HTCPEN_PORT_INIT); + synchronize_irq(HTCPEN_IRQ); +} + +static int htcpen_isa_probe(struct device *dev, unsigned int id) +{ + struct input_dev *htcpen_dev; + int err = -EBUSY; + + if (!request_region(HTCPEN_PORT_IRQ_CLEAR, 1, "htcpen")) { + printk(KERN_ERR "htcpen: unable to get IO region 0x%x\n", + HTCPEN_PORT_IRQ_CLEAR); + goto request_region1_failed; + } + + if (!request_region(HTCPEN_PORT_INIT, 1, "htcpen")) { + printk(KERN_ERR "htcpen: unable to get IO region 0x%x\n", + HTCPEN_PORT_INIT); + goto request_region2_failed; + } + + if (!request_region(HTCPEN_PORT_INDEX, 2, "htcpen")) { + printk(KERN_ERR "htcpen: unable to get IO region 0x%x\n", + HTCPEN_PORT_INDEX); + goto request_region3_failed; + } + + htcpen_dev = input_allocate_device(); + if (!htcpen_dev) { + printk(KERN_ERR "htcpen: can't allocate device\n"); + err = -ENOMEM; + goto input_alloc_failed; + } + + htcpen_dev->name = "HTC Shift EC TouchScreen"; + htcpen_dev->id.bustype = BUS_ISA; + + htcpen_dev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY); + htcpen_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + input_set_abs_params(htcpen_dev, ABS_X, 0, X_AXIS_MAX, 0, 0); + input_set_abs_params(htcpen_dev, ABS_Y, 0, Y_AXIS_MAX, 0, 0); + + htcpen_dev->open = htcpen_open; + htcpen_dev->close = htcpen_close; + + err = request_irq(HTCPEN_IRQ, htcpen_interrupt, 0, "htcpen", + htcpen_dev); + if (err) { + printk(KERN_ERR "htcpen: irq busy\n"); + goto request_irq_failed; + } + + inb_p(HTCPEN_PORT_IRQ_CLEAR); + + err = input_register_device(htcpen_dev); + if (err) + goto input_register_failed; + + dev_set_drvdata(dev, htcpen_dev); + + return 0; + + input_register_failed: + free_irq(HTCPEN_IRQ, htcpen_dev); + request_irq_failed: + input_free_device(htcpen_dev); + input_alloc_failed: + release_region(HTCPEN_PORT_INDEX, 2); + request_region3_failed: + release_region(HTCPEN_PORT_INIT, 1); + request_region2_failed: + release_region(HTCPEN_PORT_IRQ_CLEAR, 1); + request_region1_failed: + return err; +} + +static void htcpen_isa_remove(struct device *dev, unsigned int id) +{ + struct input_dev *htcpen_dev = dev_get_drvdata(dev); + + input_unregister_device(htcpen_dev); + + free_irq(HTCPEN_IRQ, htcpen_dev); + + release_region(HTCPEN_PORT_INDEX, 2); + release_region(HTCPEN_PORT_INIT, 1); + release_region(HTCPEN_PORT_IRQ_CLEAR, 1); +} + +#ifdef CONFIG_PM +static int htcpen_isa_suspend(struct device *dev, unsigned int n, + pm_message_t state) +{ + outb_p(DEVICE_DISABLE, HTCPEN_PORT_INIT); + + return 0; +} + +static int htcpen_isa_resume(struct device *dev, unsigned int n) +{ + outb_p(DEVICE_ENABLE, HTCPEN_PORT_INIT); + + return 0; +} +#endif + +static struct isa_driver htcpen_isa_driver = { + .probe = htcpen_isa_probe, + .remove = htcpen_isa_remove, +#ifdef CONFIG_PM + .suspend = htcpen_isa_suspend, + .resume = htcpen_isa_resume, +#endif + .driver = { + .owner = THIS_MODULE, + .name = "htcpen", + } +}; + +static const struct dmi_system_id htcshift_dmi_table[] __initconst = { + { + .ident = "Shift", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "High Tech Computer Corp"), + DMI_MATCH(DMI_PRODUCT_NAME, "Shift"), + }, + }, + { } +}; +MODULE_DEVICE_TABLE(dmi, htcshift_dmi_table); + +static int __init htcpen_isa_init(void) +{ + if (!dmi_check_system(htcshift_dmi_table)) + return -ENODEV; + + return isa_register_driver(&htcpen_isa_driver, 1); +} + +static void __exit htcpen_isa_exit(void) +{ + isa_unregister_driver(&htcpen_isa_driver); +} + +module_init(htcpen_isa_init); +module_exit(htcpen_isa_exit); -- cgit v1.3.1