From: Greg KH <[email protected]> 3.5-stable review patch. If anyone has any objections, please let me know.
------------------ From: Gabor Juhos <[email protected]> commit a1dca315ce3f78347bca8ce8befe3cc71ae63b7e upstream. If the controller has no PCIe module attached, accessing of the device configuration space causes a data bus error. Avoid this by checking the status of the PCIe link in advance, and indicate an error if the link is down. Signed-off-by: Gabor Juhos <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/4293/ Signed-off-by: Ralf Baechle <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/mips/pci/pci-ar724x.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) --- a/arch/mips/pci/pci-ar724x.c +++ b/arch/mips/pci/pci-ar724x.c @@ -23,9 +23,12 @@ #define AR724X_PCI_MEM_BASE 0x10000000 #define AR724X_PCI_MEM_SIZE 0x08000000 +#define AR724X_PCI_REG_RESET 0x18 #define AR724X_PCI_REG_INT_STATUS 0x4c #define AR724X_PCI_REG_INT_MASK 0x50 +#define AR724X_PCI_RESET_LINK_UP BIT(0) + #define AR724X_PCI_INT_DEV0 BIT(14) #define AR724X_PCI_IRQ_COUNT 1 @@ -38,6 +41,15 @@ static void __iomem *ar724x_pci_ctrl_bas static u32 ar724x_pci_bar0_value; static bool ar724x_pci_bar0_is_cached; +static bool ar724x_pci_link_up; + +static inline bool ar724x_pci_check_link(void) +{ + u32 reset; + + reset = __raw_readl(ar724x_pci_ctrl_base + AR724X_PCI_REG_RESET); + return reset & AR724X_PCI_RESET_LINK_UP; +} static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, uint32_t *value) @@ -46,6 +58,9 @@ static int ar724x_pci_read(struct pci_bu void __iomem *base; u32 data; + if (!ar724x_pci_link_up) + return PCIBIOS_DEVICE_NOT_FOUND; + if (devfn) return PCIBIOS_DEVICE_NOT_FOUND; @@ -96,6 +111,9 @@ static int ar724x_pci_write(struct pci_b u32 data; int s; + if (!ar724x_pci_link_up) + return PCIBIOS_DEVICE_NOT_FOUND; + if (devfn) return PCIBIOS_DEVICE_NOT_FOUND; @@ -280,6 +298,10 @@ int __init ar724x_pcibios_init(int irq) if (ar724x_pci_ctrl_base == NULL) goto err_unmap_devcfg; + ar724x_pci_link_up = ar724x_pci_check_link(); + if (!ar724x_pci_link_up) + pr_warn("ar724x: PCIe link is down\n"); + ar724x_pci_irq_init(irq); register_pci_controller(&ar724x_pci_controller); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
