/* * drivers/char/watchdog/ixp4xx_wdt.c * * Watchdog driver for Intel IXP4xx network processors * * Author: Deepak Saxena * * Copyright 2004 (c) MontaVista, Software, Inc. * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include static bool nowayout = WATCHDOG_NOWAYOUT; static int heartbeat = 60; /* (secs) Default is 1 minute */ static unsigned long wdt_status; static unsigned long boot_status; static DEFINE_SPINLOCK(wdt_lock); #define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL) #define WDT_IN_USE 0 #define WDT_OK_TO_CLOSE 1 static void wdt_enable(void) { spin_lock(&wdt_lock); *IXP4XX_OSWK = IXP4XX_WDT_KEY; *IXP4XX_OSWE = 0; *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat; *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE; *IXP4XX_OSWK = 0; spin_unlock(&wdt_lock); } static void wdt_disable(void) { spin_lock(&wdt_lock); *IXP4XX_OSWK = IXP4XX_WDT_KEY; *IXP4XX_OSWE = 0; *IXP4XX_OSWK = 0; spin_unlock(&wdt_lock); } static int ixp4xx_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(WDT_IN_USE, &wdt_status)) return -EBUSY; clear_bit(WDT_OK_TO_CLOSE, &wdt_status); wdt_enable(); return nonseekable_open(inode, file); } static ssize_t ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) { if (len) { if (!nowayout) { size_t i; clear_bit(WDT_OK_TO_CLOSE, &wdt_status); for (i = 0; i != len; i++) { char c; if (get_user(c, data + i)) return -EFAULT; if (c == 'V') set_bit(WDT_OK_TO_CLOSE, &wdt_status); } } wdt_enable(); } return len; } static const struct watchdog_info ident = { .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, .identity = "IXP4xx Watchdog", }; static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int ret = -ENOTTY; int time; switch (cmd) { case WDIOC_GETSUPPORT: ret = copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)) ? -EFAULT : 0; break; case WDIOC_GETSTATUS: ret = put_user(0, (int *)arg); break; case WDIOC_GETBOOTSTATUS: ret = put_user(boot_status, (int *)arg); break; case WDIOC_KEEPALIVE: wdt_enable(); ret = 0; break; case WDIOC_SETTIMEOUT: ret = get_user(time, (int *)arg); if (ret) break; if (time <= 0 || time > 60) { ret = -EINVAL; break; } heartbeat = time; wdt_enable(); /* Fall through */ case WDIOC_GETTIMEOUT: ret = put_user(heartbeat, (int *)arg); break; } return ret; } static int ixp4xx_wdt_release(struct inode *inode, struct file *file) { if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) wdt_disable(); else pr_crit("Device closed unexpectedly - timer will not stop\n"); clear_bit(WDT_IN_USE, &wdt_status); clear_bit(WDT_OK_TO_CLOSE, &wdt_status); return 0; } static const struct file_operations ixp4xx_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = ixp4xx_wdt_write, .unlocked_ioctl = ixp4xx_wdt_ioctl, .open = ixp4xx_wdt_open, .release = ixp4xx_wdt_release, }; static struct miscdevice ixp4xx_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &ixp4xx_wdt_fops, }; static int __init ixp4xx_wdt_init(void) { int ret; if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) { pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n"); return -ENODEV; } boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ? WDIOF_CARDRESET : 0; ret = misc_register(&ixp4xx_wdt_miscdev); if (ret == 0) pr_info("timer heartbeat %d sec\n", heartbeat); return ret; } static void __exit ixp4xx_wdt_exit(void) { misc_deregister(&ixp4xx_wdt_miscdev); } module_init(ixp4xx_wdt_init); module_exit(ixp4xx_wdt_exit); MODULE_AUTHOR("Deepak Saxena "); MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog"); module_param(heartbeat, int, 0); MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); MODULE_LICENSE("GPL"); iv>
authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2017-02-03 14:18:39 -0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-02-04 00:11:08 +0100
commit6e978b22efa1db9f6e71b24440b5f1d93e968ee3 (patch)
treec666f7a26b860674848949e39a610222b0723f89 /drivers/usb/host/xhci-tegra.c
parent3c223c19aea85d3dda1416c187915f4a30b04b1f (diff)
cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in HWP mode, even if running under sustained 100% utilization. This occurs when the HWP.EPP (Energy Performance Preference) is set to "balance_power" (0x80) -- the default on most systems. It occurs because the platform BIOS may erroneously enable an energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not recommended to be enabled on this SKU. On the failing systems, this BIOS issue was not discovered when the desktop motherboard was tested with Windows, because the BIOS also neglects to provide the ACPI/CPPC table, that Windows requires to enable HWP, and so Windows runs in legacy P-state mode, where this setting has no effect. Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and so it runs in HWP mode, exposing this incorrect BIOS configuration. There are several ways to address this problem. First, Linux can also run in legacy P-state mode on this system. As intel_pstate is how Linux enables HWP, booting with "intel_pstate=disable" will run in acpi-cpufreq/ondemand legacy p-state mode. Or second, the "performance" governor can be used with intel_pstate, which will modify HWP.EPP to 0. Or third, starting in 4.10, the /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference attribute in can be updated from "balance_power" to "performance". Or fourth, apply this patch, which fixes the erroneous setting of MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default configuration to function as designed. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Reviewed-by: Len Brown <len.brown@intel.com> Cc: 4.6+ <stable@vger.kernel.org> # 4.6+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/usb/host/xhci-tegra.c')