From 149e16372a2066c5474d8a8db9b252afd57eb427 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 23 Jul 2008 10:32:31 +0800 Subject: [PATCH] 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 ++- include/linux/pci_regs.h | 1 + 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 759c51a4e3..704605298c 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 2036300658..7098dfb074 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; diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h index 19958b9299..450684f7ea 100644 --- a/include/linux/pci_regs.h +++ b/include/linux/pci_regs.h @@ -374,6 +374,7 @@ #define PCI_EXP_DEVCAP_ATN_BUT 0x1000 /* Attention Button Present */ #define PCI_EXP_DEVCAP_ATN_IND 0x2000 /* Attention Indicator Present */ #define PCI_EXP_DEVCAP_PWR_IND 0x4000 /* Power Indicator Present */ +#define PCI_EXP_DEVCAP_RBER 0x8000 /* Role-Based Error Reporting */ #define PCI_EXP_DEVCAP_PWR_VAL 0x3fc0000 /* Slot Power Limit Value */ #define PCI_EXP_DEVCAP_PWR_SCL 0xc000000 /* Slot Power Limit Scale */ #define PCI_EXP_DEVCTL 8 /* Device Control */ -- 2.39.5