On Tuesday, May 19, 2015 11:18:42 AM Tony Lindgren wrote: > * Tony Lindgren <tony@xxxxxxxxxxx> [150519 08:21]: > > * Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> [150519 07:02]: > > > On Tuesday, May 19, 2015 04:04:43 PM Rafael J. Wysocki wrote: > > > > On Monday, May 18, 2015 04:44:01 PM Tony Lindgren wrote: > > > > > > > > > > We can replace it with just the following init and exit > > > > > time code: > > > > > > > > > > ... > > > > > device_init_wakeup(dev, true); > > > > > dev_pm_set_wake_irq(dev, irq); > > > > > ... > > > > > dev_pm_clear_wake_irq(dev); > > > > > device_init_wakeup(dev, false); > > > > > ... > > > > > > > > > > And for hardware with dedicated wake-up interrupts: > > > > > > > > > > ... > > > > > device_init_wakeup(dev, true); > > > > > dev_pm_set_dedicated_wake_irq(dev, irq); > > > > > ... > > > > > dev_pm_clear_wake_irq(dev); > > > > > device_init_wakeup(dev, false); > > > > > ... > > > > > > > > > > For now, let's only enable it for select PM_WAKEIRQ. > > > > > > > > Why? What would be wrong with doing that unconditionally? > > > > No reason to make it conditional any longer. it's there from > > the earlier version that only handled the dedicated wake IRQS. > > > > > I mean, what about making it depend on CONFIG_PM directly? > > > > OK let's do that. > > Here's the patch updated and now using just CONFIG_PM. This one looks really good. :-) If it doesn't depend on anything, I can apply it right away, so please let me know. > 8< --------------------------- > From: Tony Lindgren <tony@xxxxxxxxxxx> > Date: Mon, 18 May 2015 15:40:29 -0700 > Subject: [PATCH] PM / Wakeirq: Add automated device wake IRQ handling > > Turns out we can automate the handling for the device_may_wakeup() > quite a bit by using the kernel wakeup source list as suggested > by Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>. > > And as some hardware has separate dedicated wake-up interrupt > in addition to the IO interrupt, we can automate the handling by > adding a generic threaded interrupt handler that just calls the > device PM runtime to wake up the device. > > This allows dropping code from device drivers as we currently > are doing it in multiple ways, and often wrong. > > For most drivers, we should be able to drop the following > boilerplate code from runtime_suspend and runtime_resume > functions: > > ... > device_init_wakeup(dev, true); > ... > if (device_may_wakeup(dev)) > enable_irq_wake(irq); > ... > if (device_may_wakeup(dev)) > disable_irq_wake(irq); > ... > device_init_wakeup(dev, false); > ... > > We can replace it with just the following init and exit > time code: > > ... > device_init_wakeup(dev, true); > dev_pm_set_wake_irq(dev, irq); > ... > dev_pm_clear_wake_irq(dev); > device_init_wakeup(dev, false); > ... > > And for hardware with dedicated wake-up interrupts: > > ... > device_init_wakeup(dev, true); > dev_pm_set_dedicated_wake_irq(dev, irq); > ... > dev_pm_clear_wake_irq(dev); > device_init_wakeup(dev, false); > ... > > Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> > > diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile > index 1cb8544..f94a6cc 100644 > --- a/drivers/base/power/Makefile > +++ b/drivers/base/power/Makefile > @@ -1,4 +1,4 @@ > -obj-$(CONFIG_PM) += sysfs.o generic_ops.o common.o qos.o runtime.o > +obj-$(CONFIG_PM) += sysfs.o generic_ops.o common.o qos.o runtime.o wakeirq.o > obj-$(CONFIG_PM_SLEEP) += main.o wakeup.o > obj-$(CONFIG_PM_TRACE_RTC) += trace.o > obj-$(CONFIG_PM_OPP) += opp.o > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > index 3d874ec..6f2515c 100644 > --- a/drivers/base/power/main.c > +++ b/drivers/base/power/main.c > @@ -24,6 +24,7 @@ > #include <linux/pm.h> > #include <linux/pm_runtime.h> > #include <linux/pm-trace.h> > +#include <linux/pm_wakeirq.h> > #include <linux/interrupt.h> > #include <linux/sched.h> > #include <linux/async.h> > @@ -587,6 +588,7 @@ void dpm_resume_noirq(pm_message_t state) > async_synchronize_full(); > dpm_show_time(starttime, state, "noirq"); > resume_device_irqs(); > + device_wakeup_disarm_wake_irqs(); > cpuidle_resume(); > trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false); > } > @@ -1104,6 +1106,7 @@ int dpm_suspend_noirq(pm_message_t state) > > trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true); > cpuidle_pause(); > + device_wakeup_arm_wake_irqs(); > suspend_device_irqs(); > mutex_lock(&dpm_list_mtx); > pm_transition = state; > diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h > index b6b8a27..f1a5d95 100644 > --- a/drivers/base/power/power.h > +++ b/drivers/base/power/power.h > @@ -20,6 +20,46 @@ static inline void pm_runtime_early_init(struct device *dev) > extern void pm_runtime_init(struct device *dev); > extern void pm_runtime_remove(struct device *dev); > > +struct wake_irq { > + struct device *dev; > + int irq; > + bool dedicated_irq:1; > +}; > + > +extern void dev_pm_arm_wake_irq(struct wake_irq *wirq); > +extern void dev_pm_disarm_wake_irq(struct wake_irq *wirq); > + > +#ifdef CONFIG_PM_SLEEP > + > +extern int device_wakeup_attach_irq(struct device *dev, > + struct wake_irq *wakeirq); > +extern void device_wakeup_detach_irq(struct device *dev); > +extern void device_wakeup_arm_wake_irqs(void); > +extern void device_wakeup_disarm_wake_irqs(void); > + > +#else > + > +static inline int > +device_wakeup_attach_irq(struct device *dev, > + struct wake_irq *wakeirq) > +{ > + return 0; > +} > + > +static inline void device_wakeup_detach_irq(struct device *dev) > +{ > +} > + > +static inline void device_wakeup_arm_wake_irqs(void) > +{ > +} > + > +static inline void device_wakeup_disarm_wake_irqs(void) > +{ > +} > + > +#endif /* CONFIG_PM_SLEEP */ > + > /* > * sysfs.c > */ > @@ -52,6 +92,14 @@ static inline void wakeup_sysfs_remove(struct device *dev) {} > static inline int pm_qos_sysfs_add(struct device *dev) { return 0; } > static inline void pm_qos_sysfs_remove(struct device *dev) {} > > +static inline void dev_pm_arm_wake_irq(struct wake_irq *wirq) > +{ > +} > + > +static inline void dev_pm_disarm_wake_irq(struct wake_irq *wirq) > +{ > +} > + > #endif > > #ifdef CONFIG_PM_SLEEP > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > index 4ffe4a2..e1a10a0 100644 > --- a/drivers/base/power/runtime.c > +++ b/drivers/base/power/runtime.c > @@ -10,6 +10,7 @@ > #include <linux/sched.h> > #include <linux/export.h> > #include <linux/pm_runtime.h> > +#include <linux/pm_wakeirq.h> > #include <trace/events/rpm.h> > #include "power.h" > > @@ -514,6 +515,7 @@ static int rpm_suspend(struct device *dev, int rpmflags) > > callback = RPM_GET_CALLBACK(dev, runtime_suspend); > > + dev_pm_enable_wake_irq(dev); > retval = rpm_callback(callback, dev); > if (retval) > goto fail; > @@ -552,6 +554,7 @@ static int rpm_suspend(struct device *dev, int rpmflags) > return retval; > > fail: > + dev_pm_disable_wake_irq(dev); > __update_runtime_status(dev, RPM_ACTIVE); > dev->power.deferred_resume = false; > wake_up_all(&dev->power.wait_queue); > @@ -734,10 +737,12 @@ static int rpm_resume(struct device *dev, int rpmflags) > > callback = RPM_GET_CALLBACK(dev, runtime_resume); > > + dev_pm_disable_wake_irq(dev); > retval = rpm_callback(callback, dev); > if (retval) { > __update_runtime_status(dev, RPM_SUSPENDED); > pm_runtime_cancel_pending(dev); > + dev_pm_enable_wake_irq(dev); > } else { > no_callback: > __update_runtime_status(dev, RPM_ACTIVE); > diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c > new file mode 100644 > index 0000000..7470004 > --- /dev/null > +++ b/drivers/base/power/wakeirq.c > @@ -0,0 +1,273 @@ > +/* > + * wakeirq.c - Device wakeirq helper functions > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/device.h> > +#include <linux/interrupt.h> > +#include <linux/irq.h> > +#include <linux/slab.h> > +#include <linux/pm_runtime.h> > +#include <linux/pm_wakeirq.h> > + > +#include "power.h" > + > +/** > + * dev_pm_attach_wake_irq - Attach device interrupt as a wake IRQ > + * @dev: Device entry > + * @irq: Device wake-up capable interrupt > + * @wirq: Wake irq specific data > + * > + * Internal function to attach either a device IO interrupt or a > + * dedicated wake-up interrupt as a wake IRQ. > + */ > +static int dev_pm_attach_wake_irq(struct device *dev, int irq, > + struct wake_irq *wirq) > +{ > + unsigned long flags; > + int err; > + > + if (!dev || !wirq) > + return -EINVAL; > + > + spin_lock_irqsave(&dev->power.lock, flags); > + if (dev_WARN_ONCE(dev, dev->power.wakeirq, > + "wake irq already initialized\n")) { > + spin_unlock_irqrestore(&dev->power.lock, flags); > + return -EEXIST; > + } > + > + dev->power.wakeirq = wirq; > + spin_unlock_irqrestore(&dev->power.lock, flags); > + > + err = device_wakeup_attach_irq(dev, wirq); > + if (err) > + return err; > + > + return 0; > +} > + > +/** > + * dev_pm_set_wake_irq - Attach device IO interrupt as wake IRQ > + * @dev: Device entry > + * @irq: Device IO interrupt > + * > + * Attach a device IO interrupt as a wake IRQ. The wake IRQ gets > + * automatically configured for wake-up from suspend based > + * on the device specific sysfs wakeup entry. Typically called > + * during driver probe after calling device_init_wakeup(). > + */ > +int dev_pm_set_wake_irq(struct device *dev, int irq) > +{ > + struct wake_irq *wirq; > + int err; > + > + wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); > + if (!wirq) > + return -ENOMEM; > + > + wirq->dev = dev; > + wirq->irq = irq; > + > + err = dev_pm_attach_wake_irq(dev, irq, wirq); > + if (err) > + kfree(wirq); > + > + return err; > +} > +EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq); > + > +/** > + * dev_pm_clear_wake_irq - Detach a device IO interrupt wake IRQ > + * @dev: Device entry > + * > + * Detach a device wake IRQ and free resources. > + * > + * Note that it's OK for drivers to call this without calling > + * dev_pm_set_wake_irq() as all the driver instances may not have > + * a wake IRQ configured. This avoid adding wake IRQ specific > + * checks into the drivers. > + */ > +void dev_pm_clear_wake_irq(struct device *dev) > +{ > + struct wake_irq *wirq = dev->power.wakeirq; > + unsigned long flags; > + > + if (!wirq) > + return; > + > + spin_lock_irqsave(&dev->power.lock, flags); > + dev->power.wakeirq = NULL; > + spin_unlock_irqrestore(&dev->power.lock, flags); > + > + device_wakeup_detach_irq(dev); > + if (wirq->dedicated_irq) > + free_irq(wirq->irq, wirq); > + kfree(wirq); > +} > +EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq); > + > +/** > + * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts > + * @irq: Device specific dedicated wake-up interrupt > + * @_wirq: Wake IRQ data > + * > + * Some devices have a separate wake-up interrupt in addition to the > + * device IO interrupt. The wake-up interrupt signals that a device > + * should be woken up from it's idle state. This handler uses device > + * specific pm_runtime functions to wake the device, and then it's > + * up to the device to do whatever it needs to. Note that as the > + * device may need to restore context and start up regulators, we > + * use a threaded IRQ. > + * > + * Also note that we are not resending the lost device interrupts. > + * We assume that the wake-up interrupt just needs to wake-up the > + * device, and then device's pm_runtime_resume() can deal with the > + * situation. > + */ > +static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq) > +{ > + struct wake_irq *wirq = _wirq; > + int res; > + > + /* We don't want RPM_ASYNC or RPM_NOWAIT here */ > + res = pm_runtime_resume(wirq->dev); > + if (res < 0) > + dev_warn(wirq->dev, > + "wake IRQ with no resume: %i\n", res); > + > + return IRQ_HANDLED; > +} > + > +/** > + * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt > + * @dev: Device entry > + * @irq: Device wake-up interrupt > + * > + * Unless your hardware has separate wake-up interrupts in addition > + * to the device IO interrupts, you don't need this. > + * > + * Sets up a threaded interrupt handler for a device that has > + * a dedicated wake-up interrupt in addition to the device IO > + * interrupt. > + * > + * The interrupt starts disabled, and needs to be managed for > + * the device by the bus code or the device driver using > + * dev_pm_enable_wake_irq() and dev_pm_disable_wake_irq() > + * functions. > + */ > +int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) > +{ > + struct wake_irq *wirq; > + int err; > + > + wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); > + if (!wirq) > + return -ENOMEM; > + > + wirq->dev = dev; > + wirq->irq = irq; > + wirq->dedicated_irq = true; > + irq_set_status_flags(irq, IRQ_NOAUTOEN); > + > + /* > + * Consumer device may need to power up and restore state > + * so we use a threaded irq. > + */ > + err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq, > + IRQF_ONESHOT, dev_name(dev), wirq); > + if (err) > + goto err_free; > + > + err = dev_pm_attach_wake_irq(dev, irq, wirq); > + if (err) > + goto err_free_irq; > + > + return err; > + > +err_free_irq: > + free_irq(irq, wirq); > +err_free: > + kfree(wirq); > + > + return err; > +} > +EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); > + > +/** > + * dev_pm_enable_wake_irq - Enable device wake-up interrupt > + * @dev: Device > + * > + * Called from the bus code or the device driver for > + * runtime_suspend() to enable the wake-up interrupt while > + * the device is running. > + * > + * Note that for runtime_suspend()) the wake-up interrupts > + * should be unconditionally enabled unlike for suspend() > + * that is conditional. > + */ > +void dev_pm_enable_wake_irq(struct device *dev) > +{ > + struct wake_irq *wirq = dev->power.wakeirq; > + > + if (wirq && wirq->dedicated_irq) > + enable_irq(wirq->irq); > +} > +EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq); > + > +/** > + * dev_pm_disable_wake_irq - Disable device wake-up interrupt > + * @dev: Device > + * > + * Called from the bus code or the device driver for > + * runtime_resume() to disable the wake-up interrupt while > + * the device is running. > + */ > +void dev_pm_disable_wake_irq(struct device *dev) > +{ > + struct wake_irq *wirq = dev->power.wakeirq; > + > + if (wirq && wirq->dedicated_irq) > + disable_irq_nosync(wirq->irq); > +} > +EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq); > + > +/** > + * dev_pm_arm_wake_irq - Arm device wake-up > + * @wirq: Device wake-up interrupt > + * > + * Sets up the wake-up event conditionally based on the > + * device_may_wake(). > + */ > +void dev_pm_arm_wake_irq(struct wake_irq *wirq) > +{ > + if (!wirq) > + return; > + > + if (device_may_wakeup(wirq->dev)) > + enable_irq_wake(wirq->irq); > +} > + > +/** > + * dev_pm_disarm_wake_irq - Disarm device wake-up > + * @wirq: Device wake-up interrupt > + * > + * Clears up the wake-up event conditionally based on the > + * device_may_wake(). > + */ > +void dev_pm_disarm_wake_irq(struct wake_irq *wirq) > +{ > + if (!wirq) > + return; > + > + if (device_may_wakeup(wirq->dev)) > + disable_irq_wake(wirq->irq); > +} > diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c > index 7726200..7332ebc 100644 > --- a/drivers/base/power/wakeup.c > +++ b/drivers/base/power/wakeup.c > @@ -14,6 +14,7 @@ > #include <linux/suspend.h> > #include <linux/seq_file.h> > #include <linux/debugfs.h> > +#include <linux/pm_wakeirq.h> > #include <trace/events/power.h> > > #include "power.h" > @@ -239,6 +240,97 @@ int device_wakeup_enable(struct device *dev) > EXPORT_SYMBOL_GPL(device_wakeup_enable); > > /** > + * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source > + * @dev: Device to handle > + * @wakeirq: Device specific wakeirq entry > + * > + * Attach a device wakeirq to the wakeup source so the device > + * wake IRQ can be configured automatically for suspend and > + * resume. > + */ > +int device_wakeup_attach_irq(struct device *dev, > + struct wake_irq *wakeirq) > +{ > + struct wakeup_source *ws; > + int ret = 0; > + > + spin_lock_irq(&dev->power.lock); > + ws = dev->power.wakeup; > + if (!ws) { > + dev_err(dev, "forgot to call call device_init_wakeup?\n"); > + ret = -EINVAL; > + goto unlock; > + } > + > + if (ws->wakeirq) { > + ret = -EEXIST; > + goto unlock; > + } > + > + ws->wakeirq = wakeirq; > + > +unlock: > + spin_unlock_irq(&dev->power.lock); > + > + return ret; > +} > + > +/** > + * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source > + * @dev: Device to handle > + * > + * Removes a device wakeirq from the wakeup source. > + */ > +void device_wakeup_detach_irq(struct device *dev) > +{ > + struct wakeup_source *ws; > + > + spin_lock_irq(&dev->power.lock); > + ws = dev->power.wakeup; > + if (!ws) > + goto unlock; > + > + ws->wakeirq = NULL; > + > +unlock: > + spin_unlock_irq(&dev->power.lock); > +} > + > +/** > + * device_wakeup_arm_wake_irqs(void) > + * > + * Itereates over the list of device wakeirqs to arm them. > + */ > +void device_wakeup_arm_wake_irqs(void) > +{ > + struct wakeup_source *ws; > + > + rcu_read_lock(); > + list_for_each_entry_rcu(ws, &wakeup_sources, entry) { > + if (ws->wakeirq) > + dev_pm_arm_wake_irq(ws->wakeirq); > + } > + rcu_read_unlock(); > +} > + > +/** > + * device_wakeup_disarm_wake_irqs(void) > + * > + * Itereates over the list of device wakeirqs to disarm them. > + */ > +void device_wakeup_disarm_wake_irqs(void) > +{ > + struct wakeup_source *ws; > + > + rcu_read_lock(); > + list_for_each_entry_rcu(ws, &wakeup_sources, entry) { > + if (ws->wakeirq) > + dev_pm_disarm_wake_irq(ws->wakeirq); > + } > + rcu_read_unlock(); > +} > + > +/** > * device_wakeup_detach - Detach a device's wakeup source object from it. > * @dev: Device to detach the wakeup source object from. > * > diff --git a/include/linux/pm.h b/include/linux/pm.h > index 2d29c64..1c4ed0c 100644 > --- a/include/linux/pm.h > +++ b/include/linux/pm.h > @@ -529,6 +529,7 @@ enum rpm_request { > }; > > struct wakeup_source; > +struct wake_irq; > struct pm_domain_data; > > struct pm_subsys_data { > @@ -568,6 +569,7 @@ struct dev_pm_info { > unsigned long timer_expires; > struct work_struct work; > wait_queue_head_t wait_queue; > + struct wake_irq *wakeirq; > atomic_t usage_count; > atomic_t child_count; > unsigned int disable_depth:3; > diff --git a/include/linux/pm_wakeirq.h b/include/linux/pm_wakeirq.h > new file mode 100644 > index 0000000..4046fa1 > --- /dev/null > +++ b/include/linux/pm_wakeirq.h > @@ -0,0 +1,52 @@ > +/* > + * pm_wakeirq.h - Device wakeirq helper functions > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#ifndef _LINUX_PM_WAKEIRQ_H > +#define _LINUX_PM_WAKEIRQ_H > + > +#ifdef CONFIG_PM > + > +extern int dev_pm_set_wake_irq(struct device *dev, int irq); > +extern int dev_pm_set_dedicated_wake_irq(struct device *dev, > + int irq); > +extern void dev_pm_clear_wake_irq(struct device *dev); > +extern void dev_pm_enable_wake_irq(struct device *dev); > +extern void dev_pm_disable_wake_irq(struct device *dev); > + > +#else /* !CONFIG_PM */ > + > +static inline int dev_pm_set_wake_irq(struct device *dev, int irq) > +{ > + return 0; > +} > + > +static inline int dev_pm_set_dedicated__wake_irq(struct device *dev, > + int irq) > +{ > + return 0; > +} > + > +static inline void dev_pm_clear_wake_irq(struct device *dev) > +{ > +} > + > +static inline void dev_pm_enable_wake_irq(struct device *dev) > +{ > +} > + > +static inline void dev_pm_disable_wake_irq(struct device *dev) > +{ > +} > + > +#endif /* CONFIG_PM */ > +#endif /* _LINUX_PM_WAKEIRQ_H */ > diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h > index a0f7080..a344793 100644 > --- a/include/linux/pm_wakeup.h > +++ b/include/linux/pm_wakeup.h > @@ -28,9 +28,17 @@ > > #include <linux/types.h> > > +struct wake_irq; > + > /** > * struct wakeup_source - Representation of wakeup sources > * > + * @name: Name of the wakeup source > + * @entry: Wakeup source list entry > + * @lock: Wakeup source lock > + * @wakeirq: Optional device specific wakeirq > + * @timer: Wakeup timer list > + * @timer_expires: Wakeup timer expiration > * @total_time: Total time this wakeup source has been active. > * @max_time: Maximum time this wakeup source has been continuously active. > * @last_time: Monotonic clock when the wakeup source's was touched last time. > @@ -47,6 +55,7 @@ struct wakeup_source { > const char *name; > struct list_head entry; > spinlock_t lock; > + struct wake_irq *wakeirq; > struct timer_list timer; > unsigned long timer_expires; > ktime_t total_time; -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html