Introduce a new tunable 'hw.pci.do_power_suspend'. This tunable lets you

avoid PCI power state transition from D0 to D3 for suspending case.  Default
is 1 or enabled.

4 files changed, 12 insertions, 3 deletions

diff --git a/sys/dev/acpica/acpi_pci.c b/sys/dev/acpica/acpi_pci.c
index bf7cf2e..a14e0ba 100644
--- a/sys/dev/acpica/acpi_pci.c
+++ b/sys/dev/acpica/acpi_pci.c
@@ -179,7 +179,7 @@ acpi_pci_set_powerstate_method(device_t dev, device_t child, int state)
 	 */
 	ACPI_SERIAL_BEGIN(pci_powerstate);
 	old_state = pci_get_powerstate(child);
-	if (old_state < state) {
+	if (old_state < state && pci_do_power_suspend) {
 		error = pci_set_powerstate_method(dev, child, state);
 		if (error)
 			goto out;
diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index d1b211a..21263b7 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -257,6 +257,12 @@ SYSCTL_INT(_hw_pci, OID_AUTO, do_power_resume, CTLFLAG_RW,
     &pci_do_power_resume, 1,
   "Transition from D3 -> D0 on resume.");
 
+int pci_do_power_suspend = 1;
+TUNABLE_INT("hw.pci.do_power_suspend", &pci_do_power_suspend);
+SYSCTL_INT(_hw_pci, OID_AUTO, do_power_suspend, CTLFLAG_RW,
+    &pci_do_power_suspend, 1,
+  "Transition from D0 -> D3 on suspend.");
+
 static int pci_do_msi = 1;
 TUNABLE_INT("hw.pci.enable_msi", &pci_do_msi);
 SYSCTL_INT(_hw_pci, OID_AUTO, enable_msi, CTLFLAG_RW, &pci_do_msi, 1,
@@ -2954,7 +2960,9 @@ pci_suspend(device_t dev)
 		free(devlist, M_TEMP);
 		return (error);
 	}
-	pci_set_power_children(dev, devlist, numdevs, PCI_POWERSTATE_D3);
+	if (pci_do_power_suspend)
+		pci_set_power_children(dev, devlist, numdevs,
+		    PCI_POWERSTATE_D3);
 	free(devlist, M_TEMP);
 	return (0);
 }
diff --git a/sys/dev/pci/pci_pci.c b/sys/dev/pci/pci_pci.c
index 5dd8dbe..7915818 100644
--- a/sys/dev/pci/pci_pci.c
+++ b/sys/dev/pci/pci_pci.c
@@ -447,7 +447,7 @@ pcib_suspend(device_t dev)
 
 	pcib_cfg_save(device_get_softc(dev));
 	error = bus_generic_suspend(dev);
-	if (error == 0) {
+	if (error == 0 && pci_do_power_suspend) {
 		dstate = PCI_POWERSTATE_D3;
 		pcib = device_get_parent(device_get_parent(dev));
 		if (PCIB_POWER_FOR_SLEEP(pcib, dev, &dstate) == 0)
diff --git a/sys/dev/pci/pci_private.h b/sys/dev/pci/pci_private.h
index 70d887b..90866ef 100644
--- a/sys/dev/pci/pci_private.h
+++ b/sys/dev/pci/pci_private.h
@@ -39,6 +39,7 @@
 DECLARE_CLASS(pci_driver);
 
 extern int 	pci_do_power_resume;
+extern int 	pci_do_power_suspend;
 
 void		pci_add_children(device_t dev, int domain, int busno,
 		    size_t dinfo_size);