[PATCH 4.4 42/51] PCI: altera: Check link status before retrain link

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Ley Foon Tan <lftan@xxxxxxxxxx>

commit c622032ebc538cb3869c312ae3ad235a99da84b6 upstream.

Check the link status before retraining.  If the link is not up, don't
bother trying to retrain it.

[bhelgaas: split code move to separate patch, changelog]
Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Claudius Heine <claudius.heine.ext@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/pci/host/pcie-altera.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/pci/host/pcie-altera.c
+++ b/drivers/pci/host/pcie-altera.c
@@ -100,6 +100,10 @@ static bool altera_pcie_link_is_up(struc
 static void altera_pcie_retrain(struct pci_dev *dev)
 {
 	u16 linkcap, linkstat;
+	struct altera_pcie *pcie = dev->bus->sysdata;
+
+	if (!altera_pcie_link_is_up(pcie))
+		return;
 
 	/*
 	 * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but