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authorBjorn Helgaas <bhelgaas@google.com>2020-06-04 12:59:09 -0500
committerBjorn Helgaas <bhelgaas@google.com>2020-06-04 12:59:09 -0500
commit8ab064e93103592bb38f8e77d52e15561df619ec (patch)
tree941fde10a82dabb1b216e03dd0021b0fc2d7cae9 /drivers/pci/pcie
parent15d5a0157f31a874c94a0c8142c9bd7d494cb374 (diff)
parent11fdcf05032812bd23cdc42850d1f650376ec09d (diff)
Merge branch 'pci/enumeration'
- Fix pci_register_host_bridge() device_register() error handling (Rob Herring) - Fix pci_host_bridge struct device release/free handling (Rob Herring) - Program MPS for RCiEP devices (Ashok Raj) - Inherit PTM settings from Switch Upstream Port so we can enable PTM on Endpoints (Bjorn Helgaas) - Add #defines for bridge windows (PCI_BRIDGE_IO_WINDOW, PCI_BRIDGE_MEM_WINDOW, etc) (Krzysztof Wilczynski) * pci/enumeration: pcmcia: Use CardBus window names (PCI_CB_BRIDGE_IO_0_WINDOW etc) when freeing PCI: Use bridge window names (PCI_BRIDGE_IO_WINDOW etc) PCI/PTM: Inherit Switch Downstream Port PTM settings from Upstream Port PCI: Program MPS for RCiEP devices PCI: Fix pci_host_bridge struct device release/free handling PCI: Fix pci_register_host_bridge() device_register() error handling
Diffstat (limited to 'drivers/pci/pcie')
-rw-r--r--drivers/pci/pcie/ptm.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
index 9361f3aa26ab..357a454cafa0 100644
--- a/drivers/pci/pcie/ptm.c
+++ b/drivers/pci/pcie/ptm.c
@@ -39,10 +39,6 @@ void pci_ptm_init(struct pci_dev *dev)
if (!pci_is_pcie(dev))
return;
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);
- if (!pos)
- return;
-
/*
* Enable PTM only on interior devices (root ports, switch ports,
* etc.) on the assumption that it causes no link traffic until an
@@ -52,6 +48,23 @@ void pci_ptm_init(struct pci_dev *dev)
pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END))
return;
+ /*
+ * Switch Downstream Ports are not permitted to have a PTM
+ * capability; their PTM behavior is controlled by the Upstream
+ * Port (PCIe r5.0, sec 7.9.16).
+ */
+ ups = pci_upstream_bridge(dev);
+ if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM &&
+ ups && ups->ptm_enabled) {
+ dev->ptm_granularity = ups->ptm_granularity;
+ dev->ptm_enabled = 1;
+ return;
+ }
+
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);
+ if (!pos)
+ return;
+
pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
local_clock = (cap & PCI_PTM_GRANULARITY_MASK) >> 8;
@@ -61,7 +74,6 @@ void pci_ptm_init(struct pci_dev *dev)
* the spec recommendation (PCIe r3.1, sec 7.32.3), select the
* furthest upstream Time Source as the PTM Root.
*/
- ups = pci_upstream_bridge(dev);
if (ups && ups->ptm_enabled) {
ctrl = PCI_PTM_CTRL_ENABLE;
if (ups->ptm_granularity == 0)