On Mon, Aug 15, 2016 at 02:06:02PM +0800, Ley Foon Tan wrote:
> 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@xxxxxxxxxx>
Applied to pci/host-altera for v4.9, thanks!
> ---
> 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 2b78376..58eef99 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);
> --
> 1.8.2.1
>
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