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    SubjectRe: [PATCH 1/3] pci: Rework config space blocking services
    On Mon, 12 Sep 2011 18:54:02 +0200
    Jan Kiszka <jan.kiszka@siemens.com> wrote:

    > pci_block_user_cfg_access was designed for the use case that a single
    > context, the IPR driver, temporarily delays user space accesses to the
    > config space via sysfs. This assumption became invalid by the time
    > pci_dev_reset was added as locking instance. Today, if you run two loops
    > in parallel that reset the same device via sysfs, you end up with a
    > kernel BUG as pci_block_user_cfg_access detect the broken assumption.
    >
    > This reworks the pci_block_user_cfg_access to a sleeping service
    > pci_cfg_access_lock and an atomic-compatible variant called
    > pci_cfg_access_trylock. The former not only blocks user space access as
    > before but also waits if access was already locked. The latter service
    > just returns false in this case, allowing the caller to resolve the
    > conflict instead of raising a BUG.
    >
    > Adaptions of the ipr driver were originally written by Brian King.

    Sorry to ask you to refresh these after so long, Jan, but can you
    respin against my linux-next branch?

    My inbox is a poor substitute for patchwork, but that's no excuse for
    leaving you hanging so long. Sorry!

    Thanks,
    --
    Jesse Barnes, Intel Open Source Technology Center
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