From 5fde244d39b88625ac578d83e6625138714de031 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 23 Jul 2008 10:32:24 +0800 Subject: PCI: disable ASPM per ACPI FADT setting The ACPI FADT table includes an ASPM control bit. If the bit is set, do not enable ASPM since it may indicate that the platform doesn't actually support the feature. Tested-by: Jack Howarth Signed-off-by: Shaohua Li Signed-off-by: Jesse Barnes --- drivers/pci/pcie/aspm.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/pci/pcie/aspm.c') diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index f82495583e6..759c51a4e39 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -808,6 +808,11 @@ static int __init pcie_aspm_disable(char *str) __setup("pcie_noaspm", pcie_aspm_disable); +void pcie_no_aspm(void) +{ + aspm_disabled = 1; +} + #ifdef CONFIG_ACPI #include #include -- cgit v1.2.3-18-g5258 From 149e16372a2066c5474d8a8db9b252afd57eb427 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 23 Jul 2008 10:32:31 +0800 Subject: PCI: disable ASPM on pre-1.1 PCIe devices Disable ASPM on pre-1.1 PCIe devices, as many of them don't implement it correctly. Tested-by: Jack Howarth Signed-off-by: Shaohua Li Signed-off-by: Jesse Barnes --- drivers/pci/pcie/aspm.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'drivers/pci/pcie/aspm.c') diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 759c51a4e39..704605298c5 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -510,6 +510,7 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev) { struct pci_dev *child_dev; int child_pos; + u32 reg32; /* * Some functions in a slot might not all be PCIE functions, very @@ -519,6 +520,18 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev) child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP); if (!child_pos) return -EINVAL; + + /* + * Disable ASPM for pre-1.1 PCIe device, we follow MS to use + * RBER bit to determine if a function is 1.1 version device + */ + pci_read_config_dword(child_dev, child_pos + PCI_EXP_DEVCAP, + ®32); + if (!(reg32 & PCI_EXP_DEVCAP_RBER)) { + printk("Pre-1.1 PCIe device detected, " + "disable ASPM for %s\n", pci_name(pdev)); + return -EINVAL; + } } return 0; } -- cgit v1.2.3-18-g5258 From d6d385743463f38a0da899cd4607e526ad9a049f Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 23 Jul 2008 10:32:42 +0800 Subject: PCI: add an option to allow ASPM enabled forcibly A new option, pcie_aspm=force, will force ASPM to be enabled, even on system with PCIe 1.0 devices. Signed-off-by: Shaohua Li Signed-off-by: Jesse Barnes --- drivers/pci/pcie/aspm.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) (limited to 'drivers/pci/pcie/aspm.c') diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 704605298c5..9a7c9e1408a 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -55,7 +55,7 @@ struct pcie_link_state { struct endpoint_state endpoints[8]; }; -static int aspm_disabled; +static int aspm_disabled, aspm_force; static DEFINE_MUTEX(aspm_lock); static LIST_HEAD(link_list); @@ -527,9 +527,10 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev) */ pci_read_config_dword(child_dev, child_pos + PCI_EXP_DEVCAP, ®32); - if (!(reg32 & PCI_EXP_DEVCAP_RBER)) { + if (!(reg32 & PCI_EXP_DEVCAP_RBER && !aspm_force)) { printk("Pre-1.1 PCIe device detected, " - "disable ASPM for %s\n", pci_name(pdev)); + "disable ASPM for %s. It can be enabled forcedly" + " with 'pcie_aspm=force'\n", pci_name(pdev)); return -EINVAL; } } @@ -815,15 +816,22 @@ void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) static int __init pcie_aspm_disable(char *str) { - aspm_disabled = 1; + if (!strcmp(str, "off")) { + aspm_disabled = 1; + printk(KERN_INFO "PCIe ASPM is disabled\n"); + } else if (!strcmp(str, "force")) { + aspm_force = 1; + printk(KERN_INFO "PCIe ASPM is forcedly enabled\n"); + } return 1; } -__setup("pcie_noaspm", pcie_aspm_disable); +__setup("pcie_aspm=", pcie_aspm_disable); void pcie_no_aspm(void) { - aspm_disabled = 1; + if (!aspm_force) + aspm_disabled = 1; } #ifdef CONFIG_ACPI -- cgit v1.2.3-18-g5258