xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branch 'pci/aspm'

Browse Source 
- Use Latency Tolerance Reporting if already enabled by platform (Bjorn
    Helgaas)

  - Save/restore LTR info for suspend/resume (Bjorn Helgaas)

* pci/aspm:
  PCI/ASPM: Save LTR Capability for suspend/resume
  PCI/ASPM: Use LTR if already enabled by platform
This commit is contained in:
Bjorn Helgaas
2019-03-06 15:30:09 -06:00
parent 9d8e0e4b39 dbbfadf231
commit 2fcc19b341
2 changed files with 74 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
drivers/pci/probe.c
View File

@@ -2069,11 +2069,8 @@ static void pci_configure_ltr(struct pci_dev *dev)
{
#ifdef CONFIG_PCIEASPM
struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
u32 cap;
struct pci_dev *bridge;
if (!host->native_ltr)
return;
u32 cap, ctl;
if (!pci_is_pcie(dev))
return;
@@ -2082,22 +2079,35 @@ static void pci_configure_ltr(struct pci_dev *dev)
if (!(cap & PCI_EXP_DEVCAP2_LTR))
return;
/*
* Software must not enable LTR in an Endpoint unless the Root
* Complex and all intermediate Switches indicate support for LTR.
* PCIe r3.1, sec 6.18.
*/
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
dev->ltr_path = 1;
else {
pcie_capability_read_dword(dev, PCI_EXP_DEVCTL2, &ctl);
if (ctl & PCI_EXP_DEVCTL2_LTR_EN) {
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
dev->ltr_path = 1;
return;
}
bridge = pci_upstream_bridge(dev);
if (bridge && bridge->ltr_path)
dev->ltr_path = 1;
return;
}
if (dev->ltr_path)
if (!host->native_ltr)
return;
/*
* Software must not enable LTR in an Endpoint unless the Root
* Complex and all intermediate Switches indicate support for LTR.
* PCIe r4.0, sec 6.18.
*/
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
((bridge = pci_upstream_bridge(dev)) &&
bridge->ltr_path)) {
pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_LTR_EN);
dev->ltr_path = 1;
}
#endif
}