PCI / PM: Do not use native PCIe PME by default

Commit Message

Rafael Wysocki June 18, 2010, 3:04 p.m. UTC

None

Patch

Index: linux-2.6/drivers/pci/pcie/pme/pcie_pme.c
===================================================================
--- linux-2.6.orig/drivers/pci/pcie/pme/pcie_pme.c
+++ linux-2.6/drivers/pci/pcie/pme/pcie_pme.c
@@ -34,7 +34,7 @@ 
  * being registered.  Consequently, the interrupt-based PCIe PME signaling will
  * not be used by any PCIe root ports in that case.
  */
-static bool pcie_pme_disabled;
+static bool pcie_pme_disabled = true;
 
 /*
  * The PCI Express Base Specification 2.0, Section 6.1.8, states the following:
@@ -64,12 +64,19 @@  bool pcie_pme_msi_disabled;
 
 static int __init pcie_pme_setup(char *str)
 {
-	if (!strcmp(str, "off"))
-		pcie_pme_disabled = true;
-	else if (!strcmp(str, "force"))
+	if (!strncmp(str, "auto", 4))
+		pcie_pme_disabled = false;
+	else if (!strncmp(str, "force", 5))
 		pcie_pme_force_enable = true;
-	else if (!strcmp(str, "nomsi"))
-		pcie_pme_msi_disabled = true;
+
+	str = strchr(str, ',');
+	if (str) {
+		str++;
+		str += strspn(str, " \t");
+		if (*str && !strcmp(str, "nomsi"))
+			pcie_pme_msi_disabled = true;
+	}
+
 	return 1;
 }
 __setup("pcie_pme=", pcie_pme_setup);
Index: linux-2.6/Documentation/kernel-parameters.txt
===================================================================
--- linux-2.6.orig/Documentation/kernel-parameters.txt
+++ linux-2.6/Documentation/kernel-parameters.txt
@@ -2048,7 +2048,9 @@  and is between 256 and 4096 characters. 
 			WARNING: Forcing ASPM on may cause system lockups.
 
 	pcie_pme=	[PCIE,PM] Native PCIe PME signaling options:
-		off	Do not use native PCIe PME signaling.
+			Format: {auto|force}[,nomsi]
+		auto	Use native PCIe PME signaling if the BIOS allows the
+			kernel to control PCIe config registers of root ports.
 		force	Use native PCIe PME signaling even if the BIOS refuses
 			to allow the kernel to control the relevant PCIe config
 			registers.