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| author | Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> | 2024-05-08 14:31:38 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2024-05-08 15:08:39 -0500 |
| commit | e2e78a294a8a863898b781dbcf90e087eda3155d (patch) | |
| tree | caa099340b99214deab2940e5a9990f027f0d6b8 /drivers/pci/pcie/edr.c | |
| parent | f24ba846133d0edec785ac6430d4daf6e9c93a09 (diff) | |
| download | linux-stable-e2e78a294a8a863898b781dbcf90e087eda3155d.tar.gz linux-stable-e2e78a294a8a863898b781dbcf90e087eda3155d.tar.bz2 linux-stable-e2e78a294a8a863898b781dbcf90e087eda3155d.zip | |
PCI/EDR: Align EDR_PORT_LOCATE_DSM with PCI Firmware r3.3
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: ac1c8e35a326 ("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
Diffstat (limited to 'drivers/pci/pcie/edr.c')
| -rw-r--r-- | drivers/pci/pcie/edr.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c index fa085677c91d..e86298dbbcff 100644 --- a/drivers/pci/pcie/edr.c +++ b/drivers/pci/pcie/edr.c @@ -80,8 +80,9 @@ static struct pci_dev *acpi_dpc_port_get(struct pci_dev *pdev) u16 port; /* - * Behavior when calling unsupported _DSM functions is undefined, - * so check whether EDR_PORT_DPC_ENABLE_DSM is supported. + * If EDR_PORT_LOCATE_DSM is not implemented under the target of + * EDR, the target is the port that experienced the containment + * event (PCI Firmware r3.3, sec 4.6.13). */ if (!acpi_check_dsm(adev->handle, &pci_acpi_dsm_guid, 5, 1ULL << EDR_PORT_LOCATE_DSM)) @@ -99,6 +100,16 @@ static struct pci_dev *acpi_dpc_port_get(struct pci_dev *pdev) } /* + * Bit 31 represents the success/failure of the operation. If bit + * 31 is set, the operation failed. + */ + if (obj->integer.value & BIT(31)) { + ACPI_FREE(obj); + pci_err(pdev, "Locate Port _DSM failed\n"); + return NULL; + } + + /* * Firmware returns DPC port BDF details in following format: * 15:8 = bus * 7:3 = device |