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Commit76cde7e495(PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle) went too far with preventing pcie_pme_work_fn() from clearing the root port's PME Status and re-enabling the PME interrupt which should be done for PMEs to work correctly after system resume. The failing scenario is as follows: 1. pcie_pme_suspend() finds that the PME IRQ should be designated for system wakeup, so it calls enable_irq_wake() and then sets data->suspend_level to PME_SUSPEND_WAKEUP. 2. PME interrupt happens at this point. 3. pcie_pme_irq() runs, disables the PME interrupt and queues up the execution of pcie_pme_work_fn(). 4. pcie_pme_work_fn() runs before pcie_pme_resume() and breaks out of the loop right away, because data->suspend_level is not PME_SUSPEND_NONE, and it doesn't re-enable the PME interrupt for the same reason. 5. pcie_pme_resume() runs and simply calls disable_irq_wake() without re-enabling the PME interrupt (because data->suspend_level is not PME_SUSPEND_NONE), so the PME interrupt remains disabled and the PME Status remains set. To fix this notice that there is no reason why pcie_pme_work_fn() should behave in a special way during system resume if the PME interrupt is not disabled by pcie_pme_suspend() and partially revert commit76cde7e495and restore the previous (and correct) behavior of pcie_pme_work_fn(). Fixes:76cde7e495(PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle) Reported-and-tested-by: Naresh Solanki <naresh.solanki@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.