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    SubjectRe: [PATCH v2 0/3] PCI: Add PCI_ERROR_RESPONSE, check for errors
    On Thu, Aug 22, 2019 at 03:05:48PM -0500, Bjorn Helgaas wrote:
    > 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

    Series looks good to me.

    Reviewed-by: Keith Busch <kbusch@kernel.org>

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