diff options
| author | Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> | 2020-03-23 17:26:07 -0700 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-03-28 13:19:04 -0500 |
| commit | ac1c8e35a3262d04cc81b07fac6480a3539e3b0f (patch) | |
| tree | 503f40fea8a536d0ffa31ceb3c93f145ada48a4a /drivers/pci/pcie/Kconfig | |
| parent | aea47413e7ceec6024f5a2b743cb1a4b2176bf3f (diff) | |
| download | linux-ac1c8e35a3262d04cc81b07fac6480a3539e3b0f.tar.bz2 | |
PCI/DPC: Add Error Disconnect Recover (EDR) support
Error Disconnect Recover (EDR) is a feature that allows ACPI firmware to
notify OSPM that a device has been disconnected due to an error condition
(ACPI v6.3, sec 5.6.6). OSPM advertises its support for EDR on PCI devices
via _OSC (see [1], sec 4.5.1, table 4-4). The OSPM EDR notify handler
should invalidate software state associated with disconnected devices and
may attempt to recover them. OSPM communicates the status of recovery to
the firmware via _OST (sec 6.3.5.2).
For PCIe, firmware may use Downstream Port Containment (DPC) to support
EDR. Per [1], sec 4.5.1, table 4-6, even if firmware has retained control
of DPC, OSPM may read/write DPC control and status registers during the EDR
notification processing window, i.e., from the time it receives an EDR
notification until it clears the DPC Trigger Status.
Note that per [1], sec 4.5.1 and 4.5.2.4,
1. If the OS supports EDR, it should advertise that to firmware by
setting OSC_PCI_EDR_SUPPORT in _OSC Support.
2. If the OS sets OSC_PCI_EXPRESS_DPC_CONTROL in _OSC Control to request
control of the DPC capability, it must also set OSC_PCI_EDR_SUPPORT in
_OSC Support.
Add an EDR notify handler to attempt recovery.
[1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019,
affecting PCI Firmware Specification, Rev. 3.2
https://members.pcisig.com/wg/PCI-SIG/document/12888
[bhelgaas: squash add/enable patches into one]
Link: https://lore.kernel.org/r/90f91fe6d25c13f9d2255d2ce97ca15be307e1bb.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Diffstat (limited to 'drivers/pci/pcie/Kconfig')
| -rw-r--r-- | drivers/pci/pcie/Kconfig | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig index 6e3c04b46fb1..772b1f4cb19e 100644 --- a/drivers/pci/pcie/Kconfig +++ b/drivers/pci/pcie/Kconfig @@ -140,3 +140,13 @@ config PCIE_BW This enables PCI Express Bandwidth Change Notification. If you know link width or rate changes occur only to correct unreliable links, you may answer Y. + +config PCIE_EDR + bool "PCI Express Error Disconnect Recover support" + depends on PCIE_DPC && ACPI + help + This option adds Error Disconnect Recover support as specified + in the Downstream Port Containment Related Enhancements ECN to + the PCI Firmware Specification r3.2. Enable this if you want to + support hybrid DPC model which uses both firmware and OS to + implement DPC. |