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When the xe pm_notifier evicts for suspend / hibernate, there might be racing tasks trying to re-validate again. This can lead to suspend taking excessive time or get stuck in a live-lock. This behaviour becomes much worse with the fix that actually makes re-validation bring back bos to VRAM rather than letting them remain in TT. Prevent that by having exec and the rebind worker waiting for a completion that is set to block by the pm_notifier before suspend and is signaled by the pm_notifier after resume / wakeup. It's probably still possible to craft malicious applications that block suspending. More work is pending to fix that. v3: - Avoid wait_for_completion() in the kernel worker since it could potentially cause work item flushes from freezable processes to wait forever. Instead terminate the rebind workers if needed and re-launch at resume. (Matt Auld) v4: - Fix some bad naming and leftover debug printouts. - Fix kerneldoc. - Use drmm_mutex_init() for the xe->rebind_resume_lock (Matt Auld). - Rework the interface of xe_vm_rebind_resume_worker (Matt Auld). Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4288 Fixes:c6a4d46ec1("drm/xe: evict user memory in PM notifier") Cc: Matthew Auld <matthew.auld@intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: <stable@vger.kernel.org> # v6.16+ Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Link: https://lore.kernel.org/r/20250904160715.2613-4-thomas.hellstrom@linux.intel.com (cherry picked from commit599334572a) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>