[PATCH 9/9] PCI PM: generic suspend/resume fixes

[Adam Belay <abelay@novell.com>]

Some drivers never call pci_enable_device() or pci_enable_master() and
instead assume the bios will have initialized the device.  As a
workaround, this patch modifies the generic resume function to verify
which device features need to be enabled by checking the previous state
of the COMMAND register.  Also, pci_disable_device() is now called
during generic suspend.

Signed-off-by: Adam Belay <abelay@novell.com>

---
 pci-driver.c |   21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff -urN a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
--- a/drivers/pci/pci-driver.c	2006-05-30 21:41:14.000000000 -0400
+++ b/drivers/pci/pci-driver.c	2006-06-05 00:29:24.000000000 -0400
@@ -265,6 +265,16 @@
 	return 0;
 }
 
+/*
+ * Default suspend method for devices that have no driver provided suspend,
+ * or not even a driver at all.
+ */
+static void pci_default_suspend(struct pci_dev *pci_dev)
+{
+	pci_save_state(pci_dev);
+	pci_disable_device(pci_dev);
+}
+
 static int pci_device_suspend(struct device * dev, pm_message_t state)
 {
 	struct pci_dev * pci_dev = to_pci_dev(dev);
@@ -274,13 +284,11 @@
 	if (drv && drv->suspend) {
 		i = drv->suspend(pci_dev, state);
 		suspend_report_result(drv->suspend, i);
-	} else {
-		pci_save_state(pci_dev);
-	}
+	} else
+		pci_default_suspend(pci_dev);
 	return i;
 }
 
-
 /*
  * Default resume method for devices that have no driver provided resume,
  * or not even a driver at all.
@@ -288,14 +296,15 @@
 static void pci_default_resume(struct pci_dev *pci_dev)
 {
 	int retval;
+	u16 cmd = pci_dev->saved_config.command;
 
 	/* restore the PCI config space */
 	pci_restore_state(pci_dev);
 	/* if the device was enabled before suspend, reenable */
-	if (pci_dev->is_enabled)
+	if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
 		retval = pci_enable_device(pci_dev);
 	/* if the device was busmaster before the suspend, make it busmaster again */
-	if (pci_dev->is_busmaster)
+	if (cmd & PCI_COMMAND_MASTER)
 		pci_set_master(pci_dev);
 }