diff options
| author | Stefan Mätje <stefan.maetje@esd.eu> | 2019-03-29 20:07:34 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-25 19:26:53 +0300 |
| commit | 1c38a7b6845ed04e2fb0cf08d70c1a12ab753c41 (patch) | |
| tree | 66b1986c236205ae2a6f9c1a7ec68dc27df59d97 /drivers/pci/pcie | |
| parent | 0e21ba0f991378773b0e194c63d9703c25d5d470 (diff) | |
| download | linux-1c38a7b6845ed04e2fb0cf08d70c1a12ab753c41.tar.xz | |
PCI: Factor out pcie_retrain_link() function
commit 86fa6a344209d9414ea962b1f1ac6ade9dd7563a upstream.
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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/pci/pcie')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 40 |
1 files changed, 24 insertions, 16 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 6643a7bc381c..e83f438b036b 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -172,6 +172,29 @@ 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, ®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_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; /* @@ -221,21 +243,7 @@ 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, ®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 */ |