4.4-stable review patch. If anyone has any objections, please let me know.
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From: Ley Foon Tan lftan@altera.com
commit 3a928e98a833e1a470a60d2fedf3c55502185fb7 upstream.
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 Cc: Claudius Heine claudius.heine.ext@siemens.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/pci/host/pcie-altera.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
--- 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 p { 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 p 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);