PCI/ASPM: Factor out waiting for link training to complete

Move code polling for the Link Training bit to clear into a function of its
own.

[bhelgaas: reorder to clean up before exposing to PCI core]
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2306111605060.64925@angie.orcam.me.uk
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index e2cfff3..eaaacf2 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -193,12 +193,32 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
        link->clkpm_disable = blacklist ? 1 : 0;
 }
 
-static bool pcie_retrain_link(struct pci_dev *pdev)
+/**
+ * pcie_wait_for_link_status - Wait for link training end
+ * @pdev: Device whose link to wait for.
+ *
+ * Return TRUE if successful, or FALSE if training has not completed
+ * within LINK_RETRAIN_TIMEOUT jiffies.
+ */
+static bool pcie_wait_for_link_status(struct pci_dev *pdev)
 {
        unsigned long end_jiffies;
-       u16 lnkctl;
        u16 lnksta;
 
+       end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
+       do {
+               pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnksta);
+               if (!(lnksta & PCI_EXP_LNKSTA_LT))
+                       break;
+               msleep(1);
+       } while (time_before(jiffies, end_jiffies));
+       return !(lnksta & PCI_EXP_LNKSTA_LT);
+}
+
+static bool pcie_retrain_link(struct pci_dev *pdev)
+{
+       u16 lnkctl;
+
        pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnkctl);
        lnkctl |= PCI_EXP_LNKCTL_RL;
        pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnkctl);
@@ -212,15 +232,7 @@ static bool pcie_retrain_link(struct pci_dev *pdev)
                pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnkctl);
        }
 
-       /* Wait for link training end. Break out after waiting for timeout */
-       end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
-       do {
-               pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnksta);
-               if (!(lnksta & PCI_EXP_LNKSTA_LT))
-                       break;
-               msleep(1);
-       } while (time_before(jiffies, end_jiffies));
-       return !(lnksta & PCI_EXP_LNKSTA_LT);
+       return pcie_wait_for_link_status(pdev);
 }
 
 /*