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path: root/drivers/pci/pcie/aspm.c
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Diffstat (limited to 'drivers/pci/pcie/aspm.c')
-rw-r--r--drivers/pci/pcie/aspm.c47
1 files changed, 31 insertions, 16 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 727e3c1ef9a4..fd4cb75088f9 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -196,6 +196,36 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
link->clkpm_capable = (blacklist) ? 0 : capable;
}
+static bool pcie_retrain_link(struct pcie_link_state *link)
+{
+ struct pci_dev *parent = link->pdev;
+ unsigned long end_jiffies;
+ u16 reg16;
+
+ pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &reg16);
+ reg16 |= PCI_EXP_LNKCTL_RL;
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
+ if (parent->clear_retrain_link) {
+ /*
+ * Due to an erratum in some devices the Retrain Link bit
+ * needs to be cleared again manually to allow the link
+ * training to succeed.
+ */
+ reg16 &= ~PCI_EXP_LNKCTL_RL;
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
+ }
+
+ /* Wait for link training end. Break out after waiting for timeout */
+ end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
+ do {
+ pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16);
+ if (!(reg16 & PCI_EXP_LNKSTA_LT))
+ break;
+ msleep(1);
+ } while (time_before(jiffies, end_jiffies));
+ return !(reg16 & PCI_EXP_LNKSTA_LT);
+}
+
/*
* pcie_aspm_configure_common_clock: check if the 2 ends of a link
* could use common clock. If they are, configure them to use the
@@ -205,7 +235,6 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
{
int same_clock = 1;
u16 reg16, parent_reg, child_reg[8];
- unsigned long start_jiffies;
struct pci_dev *child, *parent = link->pdev;
struct pci_bus *linkbus = parent->subordinate;
/*
@@ -263,21 +292,7 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
reg16 &= ~PCI_EXP_LNKCTL_CCC;
pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
- /* Retrain link */
- reg16 |= PCI_EXP_LNKCTL_RL;
- pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
-
- /* Wait for link training end. Break out after waiting for timeout */
- start_jiffies = jiffies;
- for (;;) {
- pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16);
- if (!(reg16 & PCI_EXP_LNKSTA_LT))
- break;
- if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT))
- break;
- msleep(1);
- }
- if (!(reg16 & PCI_EXP_LNKSTA_LT))
+ if (pcie_retrain_link(link))
return;
/* Training failed. Restore common clock configurations */