diff mbox series

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

Message ID 20220902145835.344302-3-helgaas@kernel.org
State New
Headers show
Series None | expand

Commit Message

Bjorn Helgaas Sept. 2, 2022, 2:58 p.m. UTC 
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 mbox series

Patch

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);
 }