diff options
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 919a05b97647..79b965158473 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -15,6 +15,7 @@ #include <linux/math.h> #include <linux/module.h> #include <linux/moduleparam.h> +#include <linux/of.h> #include <linux/pci.h> #include <linux/pci_regs.h> #include <linux/errno.h> @@ -235,7 +236,8 @@ struct pcie_link_state { u32 aspm_support:7; /* Supported ASPM state */ u32 aspm_enabled:7; /* Enabled ASPM state */ u32 aspm_capable:7; /* Capable ASPM state with latency */ - u32 aspm_default:7; /* Default ASPM state by BIOS */ + u32 aspm_default:7; /* Default ASPM state by BIOS or + override */ u32 aspm_disable:7; /* Disabled ASPM state */ /* Clock PM state */ @@ -788,6 +790,27 @@ static void aspm_l1ss_init(struct pcie_link_state *link) aspm_calc_l12_info(link, parent_l1ss_cap, child_l1ss_cap); } +#define FLAG(x, y, d) (((x) & (PCIE_LINK_STATE_##y)) ? d : "") + +static void pcie_aspm_override_default_link_state(struct pcie_link_state *link) +{ + struct pci_dev *pdev = link->downstream; + u32 override; + + /* For devicetree platforms, enable L0s and L1 by default */ + if (of_have_populated_dt()) { + if (link->aspm_support & PCIE_LINK_STATE_L0S) + link->aspm_default |= PCIE_LINK_STATE_L0S; + if (link->aspm_support & PCIE_LINK_STATE_L1) + link->aspm_default |= PCIE_LINK_STATE_L1; + override = link->aspm_default & ~link->aspm_enabled; + if (override) + pci_info(pdev, "ASPM: default states%s%s\n", + FLAG(override, L0S, " L0s"), + FLAG(override, L1, " L1")); + } +} + static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) { struct pci_dev *child = link->downstream, *parent = link->pdev; @@ -868,6 +891,8 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) /* Save default state */ link->aspm_default = link->aspm_enabled; + pcie_aspm_override_default_link_state(link); + /* Setup initial capable state. Will be updated later */ link->aspm_capable = link->aspm_support; |