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 +++++++++++++ drivers/pci/probe.c | 3 ++- 2 files changed, 15 insertions(+), 1 deletion(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 759c51a4e399..704605298c5e 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; } diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 203630065839..7098dfb07449 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1057,7 +1057,8 @@ int pci_scan_slot(struct pci_bus *bus, int devfn) } } - if (bus->self) + /* only one slot has pcie device */ + if (bus->self && nr) pcie_aspm_init_link_state(bus->self); return nr; -- cgit v1.2.3