diff mbox series

[v8,2/7] PCI: Export PCI link retrain timeout

Message ID alpine.DEB.2.21.2304060110230.13659@angie.orcam.me.uk (mailing list archive)
State Superseded
Headers show
Series pci: Work around ASMedia ASM2824 PCIe link training failures | expand

Commit Message

Maciej W. Rozycki April 6, 2023, 12:21 a.m. UTC 
Rename LINK_RETRAIN_TIMEOUT to PCIE_LINK_RETRAIN_TIMEOUT and make it
available via "pci.h" for PCI drivers to use.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
---
Changes from v7:

- Reorder from 1/7.

No change from v6.

No change from v5.

New change in v5.
---
 drivers/pci/pci.h       |    2 ++
 drivers/pci/pcie/aspm.c |    4 +---
 2 files changed, 3 insertions(+), 3 deletions(-)

linux-pcie-link-retrain-timeout.diff

Comments

Bjorn Helgaas May 4, 2023, 10:21 p.m. UTC | #1 
On Thu, Apr 06, 2023 at 01:21:09AM +0100, Maciej W. Rozycki wrote:
> Rename LINK_RETRAIN_TIMEOUT to PCIE_LINK_RETRAIN_TIMEOUT and make it
> available via "pci.h" for PCI drivers to use.

> +#define PCIE_LINK_RETRAIN_TIMEOUT HZ

This is basically just a rename and move, but since we're touching it
anyway, can we make it "PCIE_LINK_RETRAIN_TIMEOUT_MS 1000" here and
use msecs_to_jiffies() below?

I know jiffies and HZ are probably idiomatic elsewhere in the kernel,
and this particular timeout is arbitrary and not based on anything in
the spec, but many of the delays in PCI *are* straight from a spec, so
I'd like to make the units more explicit.

>  extern const unsigned char pcie_link_speed[];
>  extern bool pci_early_dump;
>  
> Index: linux-macro/drivers/pci/pcie/aspm.c
> ===================================================================
> --- linux-macro.orig/drivers/pci/pcie/aspm.c
> +++ linux-macro/drivers/pci/pcie/aspm.c
> @@ -90,8 +90,6 @@ static const char *policy_str[] = {
>  	[POLICY_POWER_SUPERSAVE] = "powersupersave"
>  };
>  
> -#define LINK_RETRAIN_TIMEOUT HZ
> -
>  /*
>   * The L1 PM substate capability is only implemented in function 0 in a
>   * multi function device.
> @@ -213,7 +211,7 @@ static bool pcie_retrain_link(struct pci
>  	}
>  
>  	/* Wait for link training end. Break out after waiting for timeout */
> -	end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
> +	end_jiffies = jiffies + PCIE_LINK_RETRAIN_TIMEOUT;
>  	do {
>  		pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16);
>  		if (!(reg16 & PCI_EXP_LNKSTA_LT))
diff mbox series

Patch

Index: linux-macro/drivers/pci/pci.h
===================================================================
--- linux-macro.orig/drivers/pci/pci.h
+++ linux-macro/drivers/pci/pci.h
@@ -11,6 +11,8 @@ 
 
 #define PCI_VSEC_ID_INTEL_TBT	0x1234	/* Thunderbolt */
 
+#define PCIE_LINK_RETRAIN_TIMEOUT HZ
+
 extern const unsigned char pcie_link_speed[];
 extern bool pci_early_dump;
 
Index: linux-macro/drivers/pci/pcie/aspm.c
===================================================================
--- linux-macro.orig/drivers/pci/pcie/aspm.c
+++ linux-macro/drivers/pci/pcie/aspm.c
@@ -90,8 +90,6 @@  static const char *policy_str[] = {
 	[POLICY_POWER_SUPERSAVE] = "powersupersave"
 };
 
-#define LINK_RETRAIN_TIMEOUT HZ
-
 /*
  * The L1 PM substate capability is only implemented in function 0 in a
  * multi function device.
@@ -213,7 +211,7 @@  static bool pcie_retrain_link(struct pci
 	}
 
 	/* Wait for link training end. Break out after waiting for timeout */
-	end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
+	end_jiffies = jiffies + PCIE_LINK_RETRAIN_TIMEOUT;
 	do {
 		pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16);
 		if (!(reg16 & PCI_EXP_LNKSTA_LT))