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Although very unlikely, it is possible that cancel_work_sync() may stop the service_task before it actually started. In this case, the __FM10K_SERVICE_SCHED bit will never be cleared. This results in the service task being unable to reschedule in the future. Add a helper function which sets the service disable bit, waits for the service task to stop and clears the schedule bit, thus avoiding the race condition. We know the schedule bit is safe to clear because the cancel_work_sync() guarantees the service task is not running. Add a helper function also to restart the service task, for symmetry. This is not strictly needed but helps the mental model of how to stop and start the service task. This race could only happen in fm10k_suspend/fm10k_resume as this is the only place where the service task is actually restarted. Thus, suspend/resume testing would be ideal. However, note that the chance of this happening is very slim as the service event is scheduled for immediate execution, and you would have to trigger a suspend at almost the exact same time as the service task was scheduled. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Krishneil Singh <krishneil.k.singh@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.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.