[PATCH 0/5] PCI: Add PCI_ERROR_RESPONSE, check for errors

Bjorn Helgaas
2019-08-05T20:52:31Z

From: Bjorn Helgaas <bhelgaas@google.com>

Reads from a PCI device may fail if the device has been turned off (put
into D3cold), removed, or if some other error occurs. The PCI host bridge
typically fabricates ~0 data to complete the CPU's read.

We check for that in a few places, but not in a consistent way. This
series adds a PCI_ERROR_RESPONSE definition to make the checks more
consistent and easier to find. Note that ~0 may indicate a PCI error, but
it may also be valid read data, so you need more information (such as
knowing that a register can never contain ~0) before concluding that it's
an error.

This series also adds some new checks for PCI_ERROR_RESPONSE in the power
management code because that code frequently encounters devices in D3cold,
where we previously misinterpreted ~0 data.

Bjorn Helgaas (5):
PCI: Add PCI_ERROR_RESPONSE definition
PCI / PM: Return error when changing power state from D3cold
PCI / PM: Check for error when reading PME status
PCI / PM: Check for error when reading Power State
PCI / PM: Decode D3cold power state correctly

drivers/pci/access.c | 13 +++----
.../pci/controller/dwc/pcie-designware-host.c | 2 +-
drivers/pci/controller/pci-aardvark.c | 2 +-
drivers/pci/controller/pci-mvebu.c | 4 +-
drivers/pci/controller/pci-thunder-ecam.c | 20 +++++-----
drivers/pci/controller/pci-thunder-pem.c | 2 +-
drivers/pci/controller/pcie-altera.c | 2 +-
drivers/pci/controller/pcie-iproc.c | 2 +-
drivers/pci/controller/pcie-mediatek.c | 4 +-
drivers/pci/controller/pcie-rcar.c | 2 +-
drivers/pci/controller/pcie-rockchip-host.c | 2 +-
drivers/pci/controller/vmd.c | 2 +-
drivers/pci/hotplug/cpqphp_ctrl.c | 12 +++---
drivers/pci/hotplug/cpqphp_pci.c | 20 +++++-----
drivers/pci/hotplug/pciehp_hpc.c | 6 +--
drivers/pci/pci.c | 38 ++++++++++++-------
drivers/pci/pcie/dpc.c | 3 +-
drivers/pci/pcie/pme.c | 4 +-
drivers/pci/probe.c | 4 +-
drivers/pci/quirks.c | 2 +-
include/linux/pci.h | 20 ++++++++++
21 files changed, 98 insertions(+), 68 deletions(-)

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2.22.0.770.g0f2c4a37fd-goog