PCI/PM: Avoid putting Elo i2 PCIe Ports in D3cold
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Thu, 31 Mar 2022 17:38:51 +0000 (19:38 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 25 May 2022 07:57:27 +0000 (09:57 +0200)
commitf5012bad435d4c12681cc4049b5c19430b9ae27f
treeb1bd22d640b359f894f74d9d6a843a42e19be875
parent42d8a6dc45fc6619b8def1a70b7bd0800bcc4574
PCI/PM: Avoid putting Elo i2 PCIe Ports in D3cold

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@igel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/pci/pci.c