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  • Rafael J. Wysocki's avatar
    PCI PM: Make it possible to force using INTx for PCIe PME signaling · c39fae14
    Rafael J. Wysocki authored
    
    
    Apparently, some machines may have problems with PCI run-time power
    management if MSIs are used for the native PCIe PME signaling.  In
    particular, on the MSI Wind U-100 PCIe PME interrupts are not
    generated by a PCIe root port after a resume from suspend to RAM, if
    the system wake-up was triggered by a PME from the device attached to
    this port.  [It doesn't help to free the interrupt on suspend and
    request it back on resume, even if that is done along with disabling
    the MSI and re-enabling it, respectively.]  However, if INTx
    interrupts are used for this purpose on the same machine, everything
    works just fine.
    
    For this reason, add a kernel command line switch allowing one to
    request that MSIs be not used for the native PCIe PME signaling,
    introduce a DMI table allowing us to blacklist machines that need
    this switch to be set by default and put the MSI Wind U-100 into this
    table.
    
    Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
    Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
    c39fae14