[ Upstream commit e2e78a294a ]
The "Downstream Port Containment related Enhancements" ECN of Jan 28, 2019
(document 12888 below), defined the EDR_PORT_LOCATE_DSM function with
Revision ID 5 with a return value encoding (Bits 2:0 = Function, Bits 7:3 =
Device, Bits 15:8 = Bus). When the ECN was integrated into PCI Firmware
r3.3, sec 4.6.13, Bit 31 was added to indicate success or failure.
Check Bit 31 for failure in acpi_dpc_port_get().
Link: https://lore.kernel.org/r/20240501022543.1626025-1-sathyanarayanan.kuppuswamy@linux.intel.com
Link: https://members.pcisig.com/wg/PCI-SIG/document/12888
Fixes: ac1c8e35a3 ("PCI/DPC: Add Error Disconnect Recover (EDR) support")
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
[bhelgaas: split into two patches, update commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Satish Thatchanamurthy <Satish.Thatchanamurt@Dell.com> # one platform
Signed-off-by: Sasha Levin <sashal@kernel.org>