On Friday 01 January 2010, Rafael J. Wysocki wrote:
> On Sunday 27 December 2009, Rafael J. Wysocki wrote:
> > Hi,
> >
> > The following (updated) series of patches provides preliminary run-time power
> > management support for PCI devices through ACPI and/or the native PCIe PME.
> >
> > Some patches have been modified since the previous iteration, one patch has
> > been merged and there's one more.
> >
> > I've tested this patchset with the native PCIe PME mechanism using the r8169
> > driver on the MSI Wind U-100 (see the last patch for details) and with the ACPI
> > mechanism using the e1000e driver on the Toshiba Portege R500 (the patch still
> > requires some work to be shown in public ;-)).
>
> The e1000e patch is now in a better shape IMO, at least it worked for me in all
> conditions I tested it, so it is appended below.
This one was actually buggy, as it triggered a netdevice.h BUG_ON() during
resume from suspend to RAM with network cable attached.
Appended is a new version that doesn't have this problem and enables runtime PM
in _probe(), so the device can be put into the low power state if _open()
hasn't been called yet (or after _close()).
Rafael
---
From: Rafael J. Wysocki <rjw@xxxxxxx>
Subject: PCI / PM / e1000e: Add basic runtime PM support (rev. 2)
Use the PCI run-time power management framework to add simplified
run-time PM support to the e1000e driver. Namely, make the driver
suspend the device when the link is off and set it up for generating
wake-up event after the link has been detected again.
Based on a patch from Matthew Garrett.
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
drivers/net/e1000e/netdev.c | 130 +++++++++++++++++++++++++++++++++++---------
1 file changed, 106 insertions(+), 24 deletions(-)
Index: linux-2.6/drivers/net/e1000e/netdev.c
===================================================================
--- linux-2.6.orig/drivers/net/e1000e/netdev.c
+++ linux-2.6/drivers/net/e1000e/netdev.c
@@ -44,6 +44,7 @@
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/pm_qos_params.h>
+#include <linux/pm_runtime.h>
#include <linux/aer.h>
#include "e1000.h"
@@ -3093,12 +3094,15 @@ static int e1000_open(struct net_device
{
struct e1000_adapter *adapter = netdev_priv(netdev);
struct e1000_hw *hw = &adapter->hw;
+ struct pci_dev *pdev = adapter->pdev;
int err;
/* disallow open during test */
if (test_bit(__E1000_TESTING, &adapter->state))
return -EBUSY;
+ pm_runtime_get_sync(&pdev->dev);
+
netif_carrier_off(netdev);
/* allocate transmit descriptors */
@@ -3162,6 +3166,8 @@ static int e1000_open(struct net_device
/* fire a link status change interrupt to start the watchdog */
ew32(ICS, E1000_ICS_LSC);
+ pm_runtime_put_noidle(&pdev->dev);
+
return 0;
err_req_irq:
@@ -3172,6 +3178,7 @@ err_setup_rx:
e1000e_free_tx_resources(adapter);
err_setup_tx:
e1000e_reset(adapter);
+ pm_runtime_put_noidle(&pdev->dev);
return err;
}
@@ -3190,9 +3197,15 @@ err_setup_tx:
static int e1000_close(struct net_device *netdev)
{
struct e1000_adapter *adapter = netdev_priv(netdev);
+ struct pci_dev *pdev = adapter->pdev;
WARN_ON(test_bit(__E1000_RESETTING, &adapter->state));
- e1000e_down(adapter);
+
+ pm_runtime_get_sync(&pdev->dev);
+
+ if (!test_bit(__E1000_DOWN, &adapter->state))
+ e1000e_down(adapter);
+
e1000_power_down_phy(adapter);
e1000_free_irq(adapter);
@@ -3216,6 +3229,8 @@ static int e1000_close(struct net_device
if (adapter->flags & FLAG_HAS_AMT)
e1000_release_hw_control(adapter);
+ pm_runtime_put_noidle(&pdev->dev);
+
return 0;
}
/**
@@ -3571,6 +3586,10 @@ static void e1000_watchdog_task(struct w
if (link) {
if (!netif_carrier_ok(netdev)) {
bool txb2b = 1;
+
+ /* This is to cancel scheduled suspend requests. */
+ pm_runtime_resume(netdev->dev.parent);
+
/* update snapshot of PHY registers on LSC */
e1000_phy_read_status(adapter);
mac->ops.get_link_up_info(&adapter->hw,
@@ -3686,6 +3705,8 @@ static void e1000_watchdog_task(struct w
if (adapter->flags & FLAG_RX_NEEDS_RESTART)
schedule_work(&adapter->reset_task);
+ else
+ pm_schedule_suspend(netdev->dev.parent, 100);
}
}
@@ -4489,13 +4510,15 @@ out:
return retval;
}
-static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake)
+static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake,
+ bool runtime)
{
struct net_device *netdev = pci_get_drvdata(pdev);
struct e1000_adapter *adapter = netdev_priv(netdev);
struct e1000_hw *hw = &adapter->hw;
u32 ctrl, ctrl_ext, rctl, status;
- u32 wufc = adapter->wol;
+ /* Runtime suspend should only enable wakeup for link changes */
+ u32 wufc = runtime ? E1000_WUFC_LNKC : adapter->wol;
int retval = 0;
netif_device_detach(netdev);
@@ -4653,40 +4676,59 @@ static void e1000e_disable_l1aspm(struct
}
#ifdef CONFIG_PM
-static int e1000_suspend(struct pci_dev *pdev, pm_message_t state)
+static bool e1000e_pm_ready(struct e1000_adapter *adapter)
+{
+ return !!adapter->tx_ring->buffer_info;
+}
+
+static int e1000_idle(struct device *dev)
{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct net_device *netdev = pci_get_drvdata(pdev);
+ struct e1000_adapter *adapter = netdev_priv(netdev);
+
+ /* If we're active, prevent the driver core from changing our state */
+ if (e1000e_pm_ready(adapter))
+ return -EBUSY;
+
+ pm_schedule_suspend(dev, MSEC_PER_SEC);
+ return 0;
+}
+
+static int e1000_suspend(struct device *dev)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
int retval;
bool wake;
- retval = __e1000_shutdown(pdev, &wake);
+ retval = __e1000_shutdown(pdev, &wake, false);
if (!retval)
e1000_complete_shutdown(pdev, true, wake);
return retval;
}
-static int e1000_resume(struct pci_dev *pdev)
+static int e1000_runtime_suspend(struct device *dev)
{
+ struct pci_dev *pdev = to_pci_dev(dev);
struct net_device *netdev = pci_get_drvdata(pdev);
struct e1000_adapter *adapter = netdev_priv(netdev);
- struct e1000_hw *hw = &adapter->hw;
- u32 err;
+ bool wake;
- pci_set_power_state(pdev, PCI_D0);
- pci_restore_state(pdev);
- e1000e_disable_l1aspm(pdev);
+ if (e1000e_pm_ready(adapter))
+ return __e1000_shutdown(pdev, &wake, true);
- err = pci_enable_device_mem(pdev);
- if (err) {
- dev_err(&pdev->dev,
- "Cannot enable PCI device from suspend\n");
- return err;
- }
+ return 0;
+}
- pci_set_master(pdev);
+static int __e1000_resume(struct pci_dev *pdev)
+{
+ struct net_device *netdev = pci_get_drvdata(pdev);
+ struct e1000_adapter *adapter = netdev_priv(netdev);
+ struct e1000_hw *hw = &adapter->hw;
+ u32 err;
- pci_enable_wake(pdev, PCI_D3hot, 0);
- pci_enable_wake(pdev, PCI_D3cold, 0);
+ e1000e_disable_l1aspm(pdev);
e1000e_set_interrupt_capability(adapter);
if (netif_running(netdev)) {
@@ -4745,13 +4787,30 @@ static int e1000_resume(struct pci_dev *
return 0;
}
+
+static int e1000_resume(struct device *dev)
+{
+ return __e1000_resume(to_pci_dev(dev));
+}
+
+static int e1000_runtime_resume(struct device *dev)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct net_device *netdev = pci_get_drvdata(pdev);
+ struct e1000_adapter *adapter = netdev_priv(netdev);
+
+ if (e1000e_pm_ready(adapter))
+ return __e1000_resume(pdev);
+
+ return 0;
+}
#endif
static void e1000_shutdown(struct pci_dev *pdev)
{
bool wake = false;
- __e1000_shutdown(pdev, &wake);
+ __e1000_shutdown(pdev, &wake, false);
if (system_state == SYSTEM_POWER_OFF)
e1000_complete_shutdown(pdev, false, wake);
@@ -5231,6 +5290,11 @@ static int __devinit e1000_probe(struct
e1000_print_device_info(adapter);
+ if (pci_dev_run_wake(pdev)) {
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ }
+
return 0;
err_register:
@@ -5274,6 +5338,8 @@ static void __devexit e1000_remove(struc
struct net_device *netdev = pci_get_drvdata(pdev);
struct e1000_adapter *adapter = netdev_priv(netdev);
+ pm_runtime_get_sync(&pdev->dev);
+
/*
* flush_scheduled work may reschedule our watchdog task, so
* explicitly disable watchdog tasks from being rescheduled
@@ -5294,6 +5360,12 @@ static void __devexit e1000_remove(struc
unregister_netdev(netdev);
+ if (pci_dev_run_wake(pdev)) {
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ }
+ pm_runtime_put_noidle(&pdev->dev);
+
/*
* Release control of h/w to f/w. If f/w is AMT enabled, this
* would have already happened in close and is redundant.
@@ -5393,6 +5465,18 @@ static struct pci_device_id e1000_pci_tb
};
MODULE_DEVICE_TABLE(pci, e1000_pci_tbl);
+static const struct dev_pm_ops e1000_pm_ops = {
+ .suspend = e1000_suspend,
+ .resume = e1000_resume,
+ .freeze = e1000_suspend,
+ .thaw = e1000_resume,
+ .poweroff = e1000_suspend,
+ .restore = e1000_resume,
+ .runtime_suspend = e1000_runtime_suspend,
+ .runtime_resume = e1000_runtime_resume,
+ .runtime_idle = e1000_idle,
+};
+
/* PCI Device API Driver */
static struct pci_driver e1000_driver = {
.name = e1000e_driver_name,
@@ -5400,9 +5484,7 @@ static struct pci_driver e1000_driver =
.probe = e1000_probe,
.remove = __devexit_p(e1000_remove),
#ifdef CONFIG_PM
- /* Power Management Hooks */
- .suspend = e1000_suspend,
- .resume = e1000_resume,
+ .driver.pm = &e1000_pm_ops,
#endif
.shutdown = e1000_shutdown,
.err_handler = &e1000_err_handler
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