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DM4PR11MB7757.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Sep 2026 22:11:49.3962 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Un+s4WIyzY4wOECFWc3pxLIPVqW99v3Z71p7FtLtFr9fPO0EupalAaYaZoAfzyFQ8EV9p5DHnCDxIlE7hH56NwsF2UJ1p172dUGkOBydoOw= X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH3PPF383C22AA3 X-OriginatorOrg: intel.com X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 9/10/2026 11:42 AM, Umesh Nerlige Ramappa wrote: > get_rc6() has the same runqueue lock deadlock as guc_engine_busyness(): > it is reached from the PMU callbacks, which perf can invoke from the > scheduler with the runqueue lock held, and intel_gt_pm_put_async() there > can wake a workqueue worker via try_to_wake_up(). > > Use intel_gt_pm_put_delay() so the deferred put arms a timer instead. > > The remaining async puts in atomic contexts (hrtimer, tasklet, irq_work, > G2H handlers) cannot run with the runqueue lock held and are left alone. > > Fixes: 07779a76ee1f ("drm/i915: Mark up the calling context for intel_wakeref_put()") > Signed-off-by: Umesh Nerlige Ramappa > Assisted-by: Claude:claude-opus-5 > --- > drivers/gpu/drm/i915/i915_pmu.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c > index 1c3bafda9c70..4598d9b5678a 100644 > --- a/drivers/gpu/drm/i915/i915_pmu.c > +++ b/drivers/gpu/drm/i915/i915_pmu.c > @@ -229,7 +229,12 @@ static u64 get_rc6(struct intel_gt *gt) > wakeref = intel_gt_pm_get_if_awake(gt); > if (wakeref) { > val = __get_rc6(gt); > - intel_gt_pm_put_async(gt, wakeref); > + /* > + * We are reached from the perf callbacks, which perf may invoke rephrase "We are reached"? There is another put_async in frequency_sample(). Do we need to update that as well? Thanks, Vinay. > + * from the scheduler with the runqueue lock held. Defer the put > + * on a timer so that it can never wake a task from here. > + */ > + intel_gt_pm_put_delay(gt, wakeref, 1); > } > > spin_lock_irqsave(&pmu->lock, flags);