[PATCH 0/2] PCI PM fixes for 2.6.29

[PATCH 0/2] PCI PM fixes for 2.6.29

[Rafael J. Wysocki]

[Sorry, the previous attempt was HTML-formatted.]

Hi Jesse,

The following two patches contain fixes of PCI suspend-resume routines.

The first one corrects the suspend-resume handling for PCI Express ports after
commit 2bdc985ac3fcdb4ae9672feeb14de2c525967899 (in your tree).

The second one is a fix for devices without PM capability.

Sorry for being late with them, but I had to make sure that the first patch
doesn't break the test box affected by bug #12121 again.

Thanks,
Rafael

[PATCH 1/2] PCI PM: Split PCI Express port suspend-resume

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Suspend-resume of PCI Express ports has recently been moved into
_suspend_late() and _resume_early() callbacks, but some functions
executed from there should not be called with interrupts disabled,
eg. pci_enable_device().  For this reason, split the suspend-resume
of PCI Express ports into parts to be executed with interrupts
disabled and with interrupts enabled.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/pci/pcie/portdrv_pci.c |   23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

Index: linux-2.6/drivers/pci/pcie/portdrv_pci.c
===================================================================
--- linux-2.6.orig/drivers/pci/pcie/portdrv_pci.c
+++ linux-2.6/drivers/pci/pcie/portdrv_pci.c
@@ -41,7 +41,6 @@ static int pcie_portdrv_restore_config(s
 {
 	int retval;
 
-	pci_restore_state(dev);
 	retval = pci_enable_device(dev);
 	if (retval)
 		return retval;
@@ -50,23 +49,32 @@ static int pcie_portdrv_restore_config(s
 }
 
 #ifdef CONFIG_PM
-static int pcie_portdrv_suspend_late(struct pci_dev *dev, pm_message_t state)
+static int pcie_portdrv_suspend(struct pci_dev *dev, pm_message_t state)
 {
-	int ret = pcie_port_device_suspend(dev, state);
+	return pcie_port_device_suspend(dev, state);
+
+}
 
-	if (!ret)
-		ret = pcie_portdrv_save_config(dev);
-	return ret;
+static int pcie_portdrv_suspend_late(struct pci_dev *dev, pm_message_t state)
+{
+	return pci_save_state(dev);
 }
 
 static int pcie_portdrv_resume_early(struct pci_dev *dev)
 {
+	return pci_restore_state(dev);
+}
+
+static int pcie_portdrv_resume(struct pci_dev *dev)
+{
 	pcie_portdrv_restore_config(dev);
 	return pcie_port_device_resume(dev);
 }
 #else
+#define pcie_portdrv_suspend NULL
 #define pcie_portdrv_suspend_late NULL
 #define pcie_portdrv_resume_early NULL
+#define pcie_portdrv_resume NULL
 #endif
 
 /*
@@ -221,6 +229,7 @@ static pci_ers_result_t pcie_portdrv_slo
 
 	/* If fatal, restore cfg space for possible link reset at upstream */
 	if (dev->error_state == pci_channel_io_frozen) {
+		pci_restore_state(dev);
 		pcie_portdrv_restore_config(dev);
 		pci_enable_pcie_error_reporting(dev);
 	}
@@ -282,8 +291,10 @@ static struct pci_driver pcie_portdriver
 	.probe		= pcie_portdrv_probe,
 	.remove		= pcie_portdrv_remove,
 
+	.suspend	= pcie_portdrv_suspend,
 	.suspend_late	= pcie_portdrv_suspend_late,
 	.resume_early	= pcie_portdrv_resume_early,
+	.resume		= pcie_portdrv_resume,
 
 	.err_handler 	= &pcie_portdrv_err_handler,
 };

[PATCH 2/2] PCI PM: Fix pci_update_current_state

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Currently, PCI devices without the PM capability that are power
manageable by the platform (eg. ACPI) are not handled correctly
by pci_set_power_state(), because their current_state field is not
updated to reflect the new power state of the device.  Fix this by
making pci_update_current_state() accept additional argument
representing the power state of the device as set by the platform.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/pci/pci.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Index: linux-2.6/drivers/pci/pci.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci.c
+++ linux-2.6/drivers/pci/pci.c
@@ -524,14 +524,17 @@ pci_raw_set_power_state(struct pci_dev *
  * pci_update_current_state - Read PCI power state of given device from its
  *                            PCI PM registers and cache it
  * @dev: PCI device to handle.
+ * @state: State to cache in case the device doesn't have the PM capability
  */
-static void pci_update_current_state(struct pci_dev *dev)
+static void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
 {
 	if (dev->pm_cap) {
 		u16 pmcsr;
 
 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
 		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
+	} else {
+		dev->current_state = state;
 	}
 }
 
@@ -574,7 +577,7 @@ int pci_set_power_state(struct pci_dev *
 		 */
 		int ret = platform_pci_set_power_state(dev, PCI_D0);
 		if (!ret)
-			pci_update_current_state(dev);
+			pci_update_current_state(dev, PCI_D0);
 	}
 	/* This device is quirked not to be put into D3, so
 	   don't put it in D3 */
@@ -587,7 +590,7 @@ int pci_set_power_state(struct pci_dev *
 		/* Allow the platform to finalize the transition */
 		int ret = platform_pci_set_power_state(dev, state);
 		if (!ret) {
-			pci_update_current_state(dev);
+			pci_update_current_state(dev, state);
 			error = 0;
 		}
 	}

Re: [PATCH 1/2] PCI PM: Split PCI Express port suspend-resume

[Jesse Barnes]

On Saturday, December 27, 2008 7:28 am Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
>
> Suspend-resume of PCI Express ports has recently been moved into
> _suspend_late() and _resume_early() callbacks, but some functions
> executed from there should not be called with interrupts disabled,
> eg. pci_enable_device().  For this reason, split the suspend-resume
> of PCI Express ports into parts to be executed with interrupts
> disabled and with interrupts enabled.

Applied both of these, thanks.

-- 
Jesse Barnes, Intel Open Source Technology Center