Commit 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing") added pci_pm_power_up_and_verify_state() to pci_pm_init(). The helper ignores pci_power_up()'s return value indicating that BARs need restoring. Its resume callers restore saved configuration afterwards; pci_pm_init() does not. D3hot-to-D0 may reset a device and lose its BARs (PCI PM 1.2, sec 5.4.1). After enumeration powers it up, pci_enable_device() reads D0 and skips the full power-up path. Previously, a device still in D3hot at enable time took that path, including BAR restoration. On AMD Venice SP7, two AMD xHCI controllers [1022:17d2] are in runtime D3hot with No_Soft_Reset clear before kdump. Diagnostic reads on v7.3-rc6-37 show the following for 0000:01:00.4 in the crash kernel: PMCSR BAR0 before the platform power call 0003 f4100004 after the platform power call 0003 f4100004 after native D0 power-up 0000 00000004 The upper BAR DWORD stays zero. pci_power_up() returns 1, but the BAR address remains zero while dev->resource[0] still contains 0xf4100000. Without BAR restoration, the last console messages are around: pci 0000:01:00.4: enabling device (0000 -> 0002) Restoring both controllers' BARs gives matching readbacks and allows kdump to save a vmcore and reboot. An AMD Turin xHCI [1022:1557] shows the same BAR loss; restoring its BAR also allows kdump to complete. Use pci_set_full_power_state() in pci_pm_init() to power up the device and restore its BARs when needed. It already checks the native power state before restoring and updates ASPM when link state is present. Leave pci_pm_power_up_and_verify_state() unchanged for the resume callers, which restore saved configuration afterwards. Read the initial power state first, as pci_enable_device_flags() does. Otherwise, PCI_UNKNOWN can request a BAR restore even for devices already in D0. Keep the final pci_update_current_state() call so the final cached state still accounts for platform power and failed config reads. Suggested-by: Mario Limonciello Fixes: 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing") Cc: stable@vger.kernel.org Signed-off-by: Keng-Yu Lin --- Changes in v2: - Use pci_set_full_power_state() in pci_pm_init(), following Mario's suggestion to reuse the existing BAR restore code. - Leave the shared resume helper and its interface unchanged. - Keep the initial state readback and the final platform-aware refresh. Unlike v1, BAR restoration uses the full helper's native PMCSR check. It also updates ASPM when link state exists. Tested v2 with kdump on both systems. Normal boots made no BAR writes from this path. The crash kernels wrote only the cleared xHCI BARs: two on Venice SP7 and one on Turin. All readbacks matched. kdump saved 2.53 GB and 1.10 GB vmcores respectively before rebooting. v1: https://lore.kernel.org/r/20261008133708.947908-1-keng-yu.lin@hpe.com/ Review: https://lore.kernel.org/r/04f5463b-f123-4079-9286-06a241976d3a@amd.com/ drivers/pci/pci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 8cc6a89130b5..d3a5871e1b36 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3255,7 +3255,9 @@ void pci_pm_init(struct pci_dev *dev) } poweron: - pci_pm_power_up_and_verify_state(dev); + pci_update_current_state(dev, dev->current_state); + pci_set_full_power_state(dev, false); + pci_update_current_state(dev, PCI_D0); pm_runtime_forbid(&dev->dev); /* base-commit: 7b63ef2d55f24519e7e9e5f4d15dbea03f126e40 -- 2.43.0