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authorAaron Lu <aaron.lu@intel.com>2015-03-25 09:37:06 +0300
committerBjorn Helgaas <bhelgaas@google.com>2015-04-09 00:25:25 +0300
commite33caa82e221b0bbeba373b507e3f134dc2efa1a (patch)
tree5a5b5cb497a21c0342ac0a7d2956b366020fef68 /include/linux/pci-acpi.h
parent3390e0850b711d163b35508464cfbe0a4477dfe2 (diff)
downloadlinux-e33caa82e221b0bbeba373b507e3f134dc2efa1a.tar.xz
PCI/ACPI: Optimize device state transition delays
The PCI "ACPI additions for FW latency optimizations" ECN (link below) defines two functions in the PCI _DSM: Function 8, "Reset Delay," applies to the entire hierarchy below a PCI host bridge. If it returns one, the OS may assume that all devices in the hierarchy have already completed power-on reset delays. Function 9, "Device Readiness Durations," applies only to the object where it is located. It returns delay durations required after various events if the device requires less time than the spec requires. Delays from this function take precedence over the Reset Delay function. Add support for Reset Delay and part of Device Readiness Durations. [bhelgaas: changelog, comments] Link: https://www.pcisig.com/specifications/conventional/pci_firmware/ECN_fw_latency_optimization_final.pdf Signed-off-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'include/linux/pci-acpi.h')
-rw-r--r--include/linux/pci-acpi.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 3801c704a945..a965efa52152 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -79,6 +79,8 @@ static inline void acpiphp_check_host_bridge(struct acpi_device *adev) { }
extern const u8 pci_acpi_dsm_uuid[];
#define DEVICE_LABEL_DSM 0x07
+#define RESET_DELAY_DSM 0x08
+#define FUNCTION_DELAY_DSM 0x09
#else /* CONFIG_ACPI */
static inline void acpi_pci_add_bus(struct pci_bus *bus) { }