On Fri, Aug 19, 2016 at 4:19 AM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> 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!
Thanks, Bjorn.
>
>> ---
>> 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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