PCI/ACPI: Report ASPM support to BIOS if not disabled from command line

We need to distinguish the situation in which ASPM support is
disabled from the command line or through .config from the situation
in which it is disabled, because the hardware or BIOS can't handle
it.  In the former case we should not report ASPM support to the BIOS
through ACPI _OSC, but in the latter case we should do that.

Introduce pcie_aspm_support_enabled() that can be used by
acpi_pci_root_add() to determine whether or not it should report ASPM
support to the BIOS through _OSC.

Cc: stable@kernel.org
References: https://bugzilla.kernel.org/show_bug.cgi?id=29722
References: https://bugzilla.kernel.org/show_bug.cgi?id=20232
Reported-and-tested-by: Ortwin Glück <odi@odi.ch>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 85249395623baa32b556fbddeb77e4c71e6dfeac..c7358dd68b31c3c837714d1d8239c156ff4d8c16 100644 (file)
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -564,7 +564,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
        /* Indicate support for various _OSC capabilities. */
        if (pci_ext_cfg_avail(root->bus->self))
                flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
-       if (pcie_aspm_enabled())
+       if (pcie_aspm_support_enabled())
                flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
                        OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
        if (pci_msi_enabled())

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 3188cd96b3386c2992d2b3df1d5a7bb0e363c266..bbdb4fd85b9cf14440cb8ef6a1924b867768f4f7 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -69,6 +69,7 @@ struct pcie_link_state {
 };
 
 static int aspm_disabled, aspm_force, aspm_clear_state;
+static bool aspm_support_enabled = true;
 static DEFINE_MUTEX(aspm_lock);
 static LIST_HEAD(link_list);
 
@@ -896,6 +897,7 @@ static int __init pcie_aspm_disable(char *str)
 {
        if (!strcmp(str, "off")) {
                aspm_disabled = 1;
+               aspm_support_enabled = false;
                printk(KERN_INFO "PCIe ASPM is disabled\n");
        } else if (!strcmp(str, "force")) {
                aspm_force = 1;
@@ -930,3 +932,8 @@ int pcie_aspm_enabled(void)
 }
 EXPORT_SYMBOL(pcie_aspm_enabled);
 
+bool pcie_aspm_support_enabled(void)
+{
+       return aspm_support_enabled;
+}
+EXPORT_SYMBOL(pcie_aspm_support_enabled);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 16c9f2e61977e6f7e3192384435e43ad6aaecf9d..96f70d7e058dd043716ae216e3918567923f28bb 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1002,12 +1002,11 @@ extern bool pcie_ports_auto;
 #endif
 
 #ifndef CONFIG_PCIEASPM
-static inline int pcie_aspm_enabled(void)
-{
-       return 0;
-}
+static inline int pcie_aspm_enabled(void) { return 0; }
+static inline bool pcie_aspm_support_enabled(void) { return false; }
 #else
 extern int pcie_aspm_enabled(void);
+extern bool pcie_aspm_support_enabled(void);
 #endif
 
 #ifdef CONFIG_PCIEAER