* [PATCH] PCI: altera: Poll for link training status after retraining the link
@ 2016-08-15 6:06 Ley Foon Tan
2016-08-18 20:19 ` Bjorn Helgaas
0 siblings, 1 reply; 3+ messages in thread
From: Ley Foon Tan @ 2016-08-15 6:06 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: linux-kernel, linux-pci, Ley Foon Tan, Ley Foon Tan
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>
---
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] PCI: altera: Poll for link training status after retraining the link
2016-08-15 6:06 [PATCH] PCI: altera: Poll for link training status after retraining the link Ley Foon Tan
@ 2016-08-18 20:19 ` Bjorn Helgaas
2016-08-19 7:55 ` Ley Foon Tan
0 siblings, 1 reply; 3+ messages in thread
From: Bjorn Helgaas @ 2016-08-18 20:19 UTC (permalink / raw)
To: Ley Foon Tan; +Cc: Bjorn Helgaas, linux-kernel, linux-pci, Ley Foon Tan
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@altera.com>
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
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] PCI: altera: Poll for link training status after retraining the link
2016-08-18 20:19 ` Bjorn Helgaas
@ 2016-08-19 7:55 ` Ley Foon Tan
0 siblings, 0 replies; 3+ messages in thread
From: Ley Foon Tan @ 2016-08-19 7:55 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: Bjorn Helgaas, linux-kernel, linux-pci
On Fri, Aug 19, 2016 at 4:19 AM, Bjorn Helgaas <helgaas@kernel.org> 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@altera.com>
>
> 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
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-08-19 7:56 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2016-08-15 6:06 [PATCH] PCI: altera: Poll for link training status after retraining the link Ley Foon Tan
2016-08-18 20:19 ` Bjorn Helgaas
2016-08-19 7:55 ` Ley Foon Tan
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