PCI/ASPM: Return 0 or -ETIMEDOUT from pcie_retrain_link()

"pcie_retrain_link" is not a question with a true/false answer, so "bool"
isn't quite the right return type.  Return 0 for success or -ETIMEDOUT if
the retrain failed.  No functional change intended.

[bhelgaas: based on Ilpo's patch below]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Helgaas <[email protected]>

Author: bjorn-helgaas

drivers/pci/pcie/aspm.c

@@ -193,7 +193,7 @@ 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 pcie_link_state *link)
+static int pcie_retrain_link(struct pcie_link_state *link)
 {
 	struct pci_dev *parent = link->pdev;
 	unsigned long end_jiffies;
@@ -220,7 +220,9 @@ static bool pcie_retrain_link(struct pcie_link_state *link)
 			break;
 		msleep(1);
 	} while (time_before(jiffies, end_jiffies));
-	return !(reg16 & PCI_EXP_LNKSTA_LT);
+	if (reg16 & PCI_EXP_LNKSTA_LT)
+		return -ETIMEDOUT;
+	return 0;
 }
 
 /*
@@ -289,15 +291,15 @@ 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);
 
-	if (pcie_retrain_link(link))
-		return;
+	if (pcie_retrain_link(link)) {
 
-	/* Training failed. Restore common clock configurations */
-	pci_err(parent, "ASPM: Could not configure common clock\n");
-	list_for_each_entry(child, &linkbus->devices, bus_list)
-		pcie_capability_write_word(child, PCI_EXP_LNKCTL,
+		/* Training failed. Restore common clock configurations */
+		pci_err(parent, "ASPM: Could not configure common clock\n");
+		list_for_each_entry(child, &linkbus->devices, bus_list)
+			pcie_capability_write_word(child, PCI_EXP_LNKCTL,
 					   child_reg[PCI_FUNC(child->devfn)]);
-	pcie_capability_write_word(parent, PCI_EXP_LNKCTL, parent_reg);
+		pcie_capability_write_word(parent, PCI_EXP_LNKCTL, parent_reg);
+	}
 }
 
 /* Convert L0s latency encoding to ns */