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From: Bjorn Helgaas <helgaas@kernel.org>
To: linux-pci@vger.kernel.org
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Keith Busch <keith.busch@intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J . Wysocki" <rjw@rjwysocki.net>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Bjorn Helgaas <bhelgaas@google.com>
Subject: [PATCH v2 0/3] PCI: Add PCI_ERROR_RESPONSE, check for errors
Date: Thu, 22 Aug 2019 15:05:48 -0500
Message-ID: <20190822200551.129039-1-helgaas@kernel.org> (raw)

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 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


             reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-22 20:05 Bjorn Helgaas [this message]
2019-08-22 20:05 ` [PATCH 1/3] PCI: Add PCI_ERROR_RESPONSE definition Bjorn Helgaas
2019-08-23 10:44   ` Andrew Murray
2019-08-23 19:29     ` Bjorn Helgaas
2019-08-22 20:05 ` [PATCH 2/3] PCI / PM: Decode D3cold power state correctly Bjorn Helgaas
2019-08-22 20:05 ` [PATCH 3/3] PCI / PM: Return error when changing power state from D3cold Bjorn Helgaas
2019-08-22 21:10   ` Rafael J. Wysocki
2019-08-23  7:22 ` [PATCH v2 0/3] PCI: Add PCI_ERROR_RESPONSE, check for errors Mika Westerberg
2019-08-23 15:04 ` Keith Busch

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