2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Thomas Renninger commit 2a42d9dba7842422ffb2c02e75288a8bc2fd5065 upstream. Makes a Compaq 6735s boot reliably again. It used to hang in the loop on some boots. Give the link one second to train, otherwise break out of the loop and reset the previously set clock bits. Signed-off-by: Thomas Renninger Signed-off-by: Shaohua Li Signed-off-by: Matthew Garrett Signed-off-by: Jesse Barnes Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pcie/aspm.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include "../pci.h" @@ -161,11 +162,12 @@ static void pcie_check_clock_pm(struct p */ static void pcie_aspm_configure_common_clock(struct pci_dev *pdev) { - int pos, child_pos; + int pos, child_pos, i = 0; u16 reg16 = 0; struct pci_dev *child_dev; int same_clock = 1; - + unsigned long start_jiffies; + u16 child_regs[8], parent_reg; /* * all functions of a slot should have the same Slot Clock * Configuration, so just check one function @@ -191,16 +193,19 @@ static void pcie_aspm_configure_common_c child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP); pci_read_config_word(child_dev, child_pos + PCI_EXP_LNKCTL, ®16); + child_regs[i] = reg16; if (same_clock) reg16 |= PCI_EXP_LNKCTL_CCC; else reg16 &= ~PCI_EXP_LNKCTL_CCC; pci_write_config_word(child_dev, child_pos + PCI_EXP_LNKCTL, reg16); + i++; } /* Configure upstream component */ pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, ®16); + parent_reg = reg16; if (same_clock) reg16 |= PCI_EXP_LNKCTL_CCC; else @@ -212,12 +217,30 @@ static void pcie_aspm_configure_common_c pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16); /* Wait for link training end */ - while (1) { + /* break out after waiting for 1 second */ + start_jiffies = jiffies; + while ((jiffies - start_jiffies) < HZ) { pci_read_config_word(pdev, pos + PCI_EXP_LNKSTA, ®16); if (!(reg16 & PCI_EXP_LNKSTA_LT)) break; cpu_relax(); } + /* training failed -> recover */ + if ((jiffies - start_jiffies) >= HZ) { + dev_printk (KERN_ERR, &pdev->dev, "ASPM: Could not configure" + " common clock\n"); + i = 0; + list_for_each_entry(child_dev, &pdev->subordinate->devices, + bus_list) { + child_pos = pci_find_capability(child_dev, + PCI_CAP_ID_EXP); + pci_write_config_word(child_dev, + child_pos + PCI_EXP_LNKCTL, + child_regs[i]); + i++; + } + pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, parent_reg); + } } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/