[PATCH 4.9 39/53] PCI: Factor out pcie_retrain_link() function
From: Greg Kroah-Hartman
Date: Thu May 23 2019 - 15:53:37 EST
From: Stefan MÃtje <stefan.maetje@xxxxxx>
commit 86fa6a344209d9414ea962b1f1ac6ade9dd7563a upstream.
Factor out pcie_retrain_link() to use for Pericom Retrain Link quirk. No
functional change intended.
Signed-off-by: Stefan MÃtje <stefan.maetje@xxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/pcie/aspm.c | 40 ++++++++++++++++++++++++----------------
1 file changed, 24 insertions(+), 16 deletions(-)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -172,6 +172,29 @@ static void pcie_clkpm_cap_init(struct p
link->clkpm_capable = (blacklist) ? 0 : capable;
}
+static bool pcie_retrain_link(struct pcie_link_state *link)
+{
+ struct pci_dev *parent = link->pdev;
+ unsigned long start_jiffies;
+ u16 reg16;
+
+ pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16);
+ reg16 |= PCI_EXP_LNKCTL_RL;
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
+
+ /* Wait for link training end. Break out after waiting for timeout */
+ start_jiffies = jiffies;
+ for (;;) {
+ pcie_capability_read_word(parent, PCI_EXP_LNKSTA, ®16);
+ if (!(reg16 & PCI_EXP_LNKSTA_LT))
+ break;
+ if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT))
+ break;
+ msleep(1);
+ }
+ return !(reg16 & PCI_EXP_LNKSTA_LT);
+}
+
/*
* pcie_aspm_configure_common_clock: check if the 2 ends of a link
* could use common clock. If they are, configure them to use the
@@ -181,7 +204,6 @@ static void pcie_aspm_configure_common_c
{
int same_clock = 1;
u16 reg16, parent_reg, child_reg[8];
- unsigned long start_jiffies;
struct pci_dev *child, *parent = link->pdev;
struct pci_bus *linkbus = parent->subordinate;
/*
@@ -221,21 +243,7 @@ static void pcie_aspm_configure_common_c
reg16 &= ~PCI_EXP_LNKCTL_CCC;
pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
- /* Retrain link */
- reg16 |= PCI_EXP_LNKCTL_RL;
- pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
-
- /* Wait for link training end. Break out after waiting for timeout */
- start_jiffies = jiffies;
- for (;;) {
- pcie_capability_read_word(parent, PCI_EXP_LNKSTA, ®16);
- if (!(reg16 & PCI_EXP_LNKSTA_LT))
- break;
- if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT))
- break;
- msleep(1);
- }
- if (!(reg16 & PCI_EXP_LNKSTA_LT))
+ if (pcie_retrain_link(link))
return;
/* Training failed. Restore common clock configurations */