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authorLey Foon Tan <lftan@altera.com>2016-06-21 08:53:13 (GMT)
committerBjorn Helgaas <bhelgaas@google.com>2016-07-22 21:02:57 (GMT)
commit3a928e98a833e1a470a60d2fedf3c55502185fb7 (patch)
tree43e091a7819c1c7fccdefdc9aed21787697a21b4
parentc622032ebc538cb3869c312ae3ad235a99da84b6 (diff)
downloadlinux-3a928e98a833e1a470a60d2fedf3c55502185fb7.tar.xz
PCI: altera: Poll for link up status after retraining the link
Some PCIe devices take a long time to reach link up state after retrain. Poll for link up status after retraining the link. This is to make sure the link is up before we access configuration space. [bhelgaas: changelog] Signed-off-by: Ley Foon Tan <lftan@altera.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
-rw-r--r--drivers/pci/host/pcie-altera.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/pci/host/pcie-altera.c b/drivers/pci/host/pcie-altera.c
index b61025e..e4154b2 100644
--- a/drivers/pci/host/pcie-altera.c
+++ b/drivers/pci/host/pcie-altera.c
@@ -61,6 +61,8 @@
#define TLP_LOOP 500
#define RP_DEVFN 0
+#define LINK_UP_TIMEOUT 5000
+
#define INTX_NUM 4
#define DWORD_MASK 3
@@ -101,6 +103,7 @@ static void altera_pcie_retrain(struct pci_dev *dev)
{
u16 linkcap, linkstat;
struct altera_pcie *pcie = dev->bus->sysdata;
+ int timeout = 0;
if (!altera_pcie_link_is_up(pcie))
return;
@@ -115,9 +118,16 @@ static void altera_pcie_retrain(struct pci_dev *dev)
return;
pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
- if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB)
+ if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
pcie_capability_set_word(dev, PCI_EXP_LNKCTL,
PCI_EXP_LNKCTL_RL);
+ while (!altera_pcie_link_is_up(pcie)) {
+ timeout++;
+ if (timeout > LINK_UP_TIMEOUT)
+ break;
+ udelay(5);
+ }
+ }
}
DECLARE_PCI_FIXUP_EARLY(0x1172, PCI_ANY_ID, altera_pcie_retrain);