From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
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 a new check for PCI_ERROR_RESPONSE in the power
management code because that code frequently encounters devices in D3cold,
where we previously misinterpreted ~0 data. It also uses pci_power_name()
to print D-state names more consistently.
Rafael, I didn't add your Reviewed-by to "PCI / PM: Return error when
changing power state from D3cold" because I made small changes to try to
make the messages more consistent, and I didn't want to presume they'd be
OK with you.
Changes since v1:
- Add Rafael's Reviewed-By to the first two patches
- Drop "PCI / PM: Check for error when reading PME status" because Rafael
pointed out that some devices can signal PME even when in D3cold, so
this would require additional rework
- Drop "PCI / PM: Check for error when reading Power State" because
Rafael thinks it's mostly redundant
Bjorn Helgaas (3):
PCI: Add PCI_ERROR_RESPONSE definition
PCI / PM: Decode D3cold power state correctly
PCI / PM: Return error when changing power state from D3cold
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 | 31 ++++++++++++-------
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 | 7 +++++
21 files changed, 81 insertions(+), 65 deletions(-)
--
2.23.0.187.g17f5b7556c-goog
