From: Ley Foon Tan lftan@altera.com
commit 411dc32d8810e0a204c799ce5c97cb56990de1cb upstream
Poll for link training status is cleared before poll for link up status. This can help to get the reliable link up status, especially when PCIe is in Gen 3 speed.
Signed-off-by: Ley Foon Tan lftan@altera.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Claudius Heine ch@denx.de --- drivers/pci/host/pcie-altera.c | 45 ++++++++++++++++++++++++++++------ 1 file changed, 37 insertions(+), 8 deletions(-)
diff --git a/drivers/pci/host/pcie-altera.c b/drivers/pci/host/pcie-altera.c index e4154b2a23ce..e0be9ac5701a 100644 --- a/drivers/pci/host/pcie-altera.c +++ b/drivers/pci/host/pcie-altera.c @@ -61,7 +61,8 @@ #define TLP_LOOP 500 #define RP_DEVFN 0
-#define LINK_UP_TIMEOUT 5000 +#define LINK_UP_TIMEOUT HZ +#define LINK_RETRAIN_TIMEOUT HZ
#define INTX_NUM 4
@@ -99,11 +100,44 @@ static bool altera_pcie_link_is_up(struct altera_pcie *pcie) return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0); }
+static void altera_wait_link_retrain(struct pci_dev *dev) +{ + u16 reg16; + unsigned long start_jiffies; + struct altera_pcie *pcie = dev->bus->sysdata; + + /* Wait for link training end. */ + start_jiffies = jiffies; + for (;;) { + pcie_capability_read_word(dev, PCI_EXP_LNKSTA, ®16); + if (!(reg16 & PCI_EXP_LNKSTA_LT)) + break; + + if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) { + dev_err(&pcie->pdev->dev, "link retrain timeout\n"); + break; + } + udelay(100); + } + + /* Wait for link is up */ + start_jiffies = jiffies; + for (;;) { + if (altera_pcie_link_is_up(pcie)) + break; + + if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) { + dev_err(&pcie->pdev->dev, "link up timeout\n"); + break; + } + udelay(100); + } +} + 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; @@ -121,12 +155,7 @@ static void altera_pcie_retrain(struct pci_dev *dev) 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); - } + altera_wait_link_retrain(dev); } } DECLARE_PCI_FIXUP_EARLY(0x1172, PCI_ANY_ID, altera_pcie_retrain);