Merge branch 'pci/aspm' into next

* pci/aspm:
  PCI/ASPM: Don't retrain link if ASPM not possible
  PCI/ASPM: Use permission-specific DEVICE_ATTR variants

drivers/pci/pcie/aspm.c

@@ -351,12 +351,26 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
 		return;
 	}
 
+	/* Get upstream/downstream components' register state */
+	pcie_get_aspm_reg(parent, &upreg);
+	child = list_entry(linkbus->devices.next, struct pci_dev, bus_list);
+	pcie_get_aspm_reg(child, &dwreg);
+
+	/*
+	 * If ASPM not supported, don't mess with the clocks and link,
+	 * bail out now.
+	 */
+	if (!(upreg.support & dwreg.support))
+		return;
+
 	/* Configure common clock before checking latencies */
 	pcie_aspm_configure_common_clock(link);
 
-	/* Get upstream/downstream components' register state */
+	/*
+	 * Re-read upstream/downstream components' register state
+	 * after clock configuration
+	 */
 	pcie_get_aspm_reg(parent, &upreg);
-	child = list_entry(linkbus->devices.next, struct pci_dev, bus_list);
 	pcie_get_aspm_reg(child, &dwreg);
 
 	/*
@@ -886,8 +900,8 @@ static ssize_t clk_ctl_store(struct device *dev,
 	return n;
 }
 
-static DEVICE_ATTR(link_state, 0644, link_state_show, link_state_store);
-static DEVICE_ATTR(clk_ctl, 0644, clk_ctl_show, clk_ctl_store);
+static DEVICE_ATTR_RW(link_state);
+static DEVICE_ATTR_RW(clk_ctl);
 
 static char power_group[] = "power";
 void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)