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PCI: Factor out pcie_retrain_link() function

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Factor out pcie_retrain_link() to use for Pericom Retrain Link quirk.  No
functional change intended.

Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: stable@vger.kernel.org
This commit is contained in:
Stefan Mätje 2019-03-29 18:07:34 +01:00 committed by Bjorn Helgaas
parent 6302bf3ef7
commit 86fa6a3442
1 changed files with 24 additions and 16 deletions
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40
drivers/pci/pcie/aspm.c
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@ -196,6 +196,29 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
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, &reg16);
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, &reg16);
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
@ -205,7 +228,6 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
{
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;
/*
@ -263,21 +285,7 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
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, &reg16);
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 */