This is a note to let you know that I've just added the patch titled PCI/PM: Avoid putting Elo i2 PCIe Ports in D3cold to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pci-pm-avoid-putting-elo-i2-pcie-ports-in-d3cold.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 92597f97a40bf661bebceb92e26ff87c76d562d4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> Date: Thu, 31 Mar 2022 19:38:51 +0200 Subject: PCI/PM: Avoid putting Elo i2 PCIe Ports in D3cold From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> commit 92597f97a40bf661bebceb92e26ff87c76d562d4 upstream. If a Root Port on Elo i2 is put into D3cold and then back into D0, the downstream device becomes permanently inaccessible, so add a bridge D3 DMI quirk for that system. This was exposed by 14858dcc3b35 ("PCI: Use pci_update_current_state() in pci_enable_device_flags()"), but before that commit the Root Port in question had never been put into D3cold for real due to a mismatch between its power state retrieved from the PCI_PM_CTRL register (which was accessible even though the platform firmware indicated that the port was in D3cold) and the state of an ACPI power resource involved in its power management. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215715 Link: https://lore.kernel.org/r/11980172.O9o76ZdvQC@kreacher Reported-by: Stefan Gottwald <gottwald@xxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # v5.15+ Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/pci.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2888,6 +2888,16 @@ static const struct dmi_system_id bridge DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."), DMI_MATCH(DMI_BOARD_NAME, "X299 DESIGNARE EX-CF"), }, + /* + * Downstream device is not accessible after putting a root port + * into D3cold and back into D0 on Elo i2. + */ + .ident = "Elo i2", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Elo Touch Solutions"), + DMI_MATCH(DMI_PRODUCT_NAME, "Elo i2"), + DMI_MATCH(DMI_PRODUCT_VERSION, "RevB"), + }, }, #endif { } Patches currently in stable-queue which might be from rafael.j.wysocki@xxxxxxxxx are queue-5.15/pci-pm-avoid-putting-elo-i2-pcie-ports-in-d3cold.patch