[PATCH 3.16 020/132] PCI: Factor out pcie_retrain_link() function

[Ben Hutchings]

3.16.74-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Mätje <stefan.mae...@esd.eu>

commit 86fa6a344209d9414ea962b1f1ac6ade9dd7563a upstream.

Factor out pcie_retrain_link() to use for Pericom Retrain Link quirk.  No
functional change intended.

Signed-off-by: Stefan Mätje <stefan.mae...@esd.eu>
Signed-off-by: Bjorn Helgaas <bhelg...@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/pci/pcie/aspm.c | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -175,6 +175,29 @@ static void pcie_clkpm_cap_init(struct p
        link->clkpm_capable = (blacklist) ? 0 : capable;
 }
 
+static bool pcie_retrain_link(struct pcie_link_state *link)
+{
+       struct pci_dev *parent = link->pdev;
+       unsigned long start_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);
+
+       /* 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);
+       }
+       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
@@ -184,7 +207,6 @@ static void pcie_aspm_configure_common_c
 {
        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;
        /*
@@ -224,21 +246,7 @@ static void pcie_aspm_configure_common_c
                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 */