[PATCH 2/4] PCI/PTM: Enable PTM when restoring state

Bjorn Helgaas
2022-09-02T15:26:21Z

From: Bjorn Helgaas <bhelgaas@google.com>

The suspend path may disable PTM before saving config state, which means
the PCI_PTM_CTRL_ENABLE bit in the saved state may be cleared even though
we want PTM to be enabled when resuming.

If "dev->ptm_enabled" is set, it means PTM should be enabled, so make sure
PCI_PTM_CTRL_ENABLE is set when restoring the PTM state.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/pcie/ptm.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
index b6a417247ce3..3115601a85ef 100644
--- a/drivers/pci/pcie/ptm.c
+++ b/drivers/pci/pcie/ptm.c
@@ -82,6 +82,14 @@ void pci_restore_ptm_state(struct pci_dev *dev)
return;

cap = (u16 *)&save_state->cap.data[0];
+
+ /*
+ * The suspend path may disable PTM before saving config state.
+ * Make sure PCI_PTM_CTRL_ENABLE is set if PTM should be enabled.
+ */
+ if (dev->ptm_enabled)
+ *cap |= PCI_PTM_CTRL_ENABLE;
+
pci_write_config_word(dev, ptm + PCI_PTM_CTRL, *cap);
}

--
2.25.1