PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch

[linux-2.6-omap-h63xx.git] / drivers / pci / pcie / aspm.c

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 8f63f4c6b85f64e3f4d91d76ca7da90ac142c51e..9aad608bcf3fb947dac183a2153312a6ce5db962 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -16,6 +16,7 @@
 #include <linux/pm.h>
 #include <linux/init.h>
 #include <linux/slab.h>
+#include <linux/jiffies.h>
 #include <linux/pci-aspm.h>
 #include "../pci.h"
 
@@ -161,11 +162,12 @@ static void pcie_check_clock_pm(struct pci_dev *pdev)
  */
 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_clock(struct pci_dev *pdev)
                child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
                pci_read_config_word(child_dev, child_pos + PCI_EXP_LNKCTL,
                        &reg16);
+               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, &reg16);
+       parent_reg = reg16;
        if (same_clock)
                reg16 |= PCI_EXP_LNKCTL_CCC;
        else
@@ -212,12 +217,30 @@ static void pcie_aspm_configure_common_clock(struct pci_dev *pdev)
        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, &reg16);
                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);
+       }
 }
 
 /*