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Fri, 26 Jun 2026 02:11:24 -0700 (PDT) Received: from [192.168.0.1] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DDCA13F836 for ; Fri, 26 Jun 2026 02:11:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1782465089; bh=jm7egqUyEzW6DOGD9yfCsukCGAJ2Ls8ut4uVYSyLZc4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jBSVO8vyOkG540vwk2xIqp6jnQqQXnWYoenX+rP+SgaiYnZxFqM9hLb+X58iFbBu/ w9yzY1AUt6Xuus9auqSicdWkryzCt3mlpn6OEhF2RN3vM0B1DZLMPjnK+jCN15uzar 31fwpKPiiKEixRl+o+uHihCukm2JIXThYi6jF6to= Date: Fri, 26 Jun 2026 10:11:17 +0100 From: Liviu Dudau To: Boris Brezillon Cc: Steven Price , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Nicolas Frattaroli , Chia-I Wu , Karunika Choo , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, sashiko-bot@kernel.org Subject: Re: [PATCH 01/11] drm/panthor: Always use the IRQ-safe variant when acquiring the fence lock Message-ID: References: <20260625-panthor-misc-fixes-v1-0-b67ed973fea6@collabora.com> <20260625-panthor-misc-fixes-v1-1-b67ed973fea6@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260625-panthor-misc-fixes-v1-1-b67ed973fea6@collabora.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Jun 25, 2026 at 02:40:27PM +0200, Boris Brezillon wrote: > Since dma_fence objects can be shared with other subsystems, they may be > accessed from hardirq context in those drivers, and we have to take > that into account by also using the IRQ-safe variant when acquiring > the lock. > > While at it, switch to the guard model. > > Fixes: de8548813824 ("drm/panthor: Add the scheduler logical block") > Reported-by: sashiko-bot@kernel.org > Closes: https://sashiko.dev/#/patchset/20260625-panthor-signal-from-irq-v5-0-8836a74e0ef9@collabora.com?part=11 > Signed-off-by: Boris Brezillon Reviewed-by: Liviu Dudau Best regards, Liviu > --- > drivers/gpu/drm/panthor/panthor_sched.c | 83 ++++++++++++++++----------------- > 1 file changed, 39 insertions(+), 44 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c > index 5b34032deff8..e97f29469d28 100644 > --- a/drivers/gpu/drm/panthor/panthor_sched.c > +++ b/drivers/gpu/drm/panthor/panthor_sched.c > @@ -1151,15 +1151,14 @@ queue_suspend_timeout_locked(struct panthor_queue *queue) > static void > queue_suspend_timeout(struct panthor_queue *queue) > { > - spin_lock(&queue->fence_ctx.lock); > + guard(spinlock_irqsave)(&queue->fence_ctx.lock); > queue_suspend_timeout_locked(queue); > - spin_unlock(&queue->fence_ctx.lock); > } > > static void > queue_resume_timeout(struct panthor_queue *queue) > { > - spin_lock(&queue->fence_ctx.lock); > + guard(spinlock_irqsave)(&queue->fence_ctx.lock); > > if (queue_timeout_is_suspended(queue)) { > mod_delayed_work(queue->scheduler.timeout_wq, > @@ -1168,8 +1167,6 @@ queue_resume_timeout(struct panthor_queue *queue) > > queue->timeout.remaining = MAX_SCHEDULE_TIMEOUT; > } > - > - spin_unlock(&queue->fence_ctx.lock); > } > > /** > @@ -1542,7 +1539,7 @@ cs_slot_process_fault_event_locked(struct panthor_device *ptdev, > u64 cs_extract = queue->iface.output->extract; > struct panthor_job *job; > > - spin_lock(&queue->fence_ctx.lock); > + guard(spinlock_irqsave)(&queue->fence_ctx.lock); > list_for_each_entry(job, &queue->fence_ctx.in_flight_jobs, node) { > if (cs_extract >= job->ringbuf.end) > continue; > @@ -1552,7 +1549,6 @@ cs_slot_process_fault_event_locked(struct panthor_device *ptdev, > > dma_fence_set_error(job->done_fence, -EINVAL); > } > - spin_unlock(&queue->fence_ctx.lock); > } > > if (group) { > @@ -2183,13 +2179,13 @@ group_term_post_processing(struct panthor_group *group) > if (!queue) > continue; > > - spin_lock(&queue->fence_ctx.lock); > - list_for_each_entry_safe(job, tmp, &queue->fence_ctx.in_flight_jobs, node) { > - list_move_tail(&job->node, &faulty_jobs); > - dma_fence_set_error(job->done_fence, err); > - dma_fence_signal_locked(job->done_fence); > + scoped_guard(spinlock_irqsave, &queue->fence_ctx.lock) { > + list_for_each_entry_safe(job, tmp, &queue->fence_ctx.in_flight_jobs, node) { > + list_move_tail(&job->node, &faulty_jobs); > + dma_fence_set_error(job->done_fence, err); > + dma_fence_signal_locked(job->done_fence); > + } > } > - spin_unlock(&queue->fence_ctx.lock); > > /* Manually update the syncobj seqno to unblock waiters. */ > syncobj = group->syncobjs->kmap + (i * sizeof(*syncobj)); > @@ -3049,39 +3045,39 @@ static bool queue_check_job_completion(struct panthor_queue *queue) > LIST_HEAD(done_jobs); > > cookie = dma_fence_begin_signalling(); > - spin_lock(&queue->fence_ctx.lock); > - list_for_each_entry_safe(job, job_tmp, &queue->fence_ctx.in_flight_jobs, node) { > - if (!syncobj) { > - struct panthor_group *group = job->group; > + scoped_guard(spinlock_irqsave, &queue->fence_ctx.lock) { > + list_for_each_entry_safe(job, job_tmp, &queue->fence_ctx.in_flight_jobs, node) { > + if (!syncobj) { > + struct panthor_group *group = job->group; > > - syncobj = group->syncobjs->kmap + > - (job->queue_idx * sizeof(*syncobj)); > + syncobj = group->syncobjs->kmap + > + (job->queue_idx * sizeof(*syncobj)); > + } > + > + if (syncobj->seqno < job->done_fence->seqno) > + break; > + > + list_move_tail(&job->node, &done_jobs); > + dma_fence_signal_locked(job->done_fence); > } > > - if (syncobj->seqno < job->done_fence->seqno) > - break; > + if (list_empty(&queue->fence_ctx.in_flight_jobs)) { > + /* If we have no job left, we cancel the timer, and reset remaining > + * time to its default so it can be restarted next time > + * queue_resume_timeout() is called. > + */ > + queue_suspend_timeout_locked(queue); > > - list_move_tail(&job->node, &done_jobs); > - dma_fence_signal_locked(job->done_fence); > + /* If there's no job pending, we consider it progress to avoid a > + * spurious timeout if the timeout handler and the sync update > + * handler raced. > + */ > + progress = true; > + } else if (!list_empty(&done_jobs)) { > + queue_reset_timeout_locked(queue); > + progress = true; > + } > } > - > - if (list_empty(&queue->fence_ctx.in_flight_jobs)) { > - /* If we have no job left, we cancel the timer, and reset remaining > - * time to its default so it can be restarted next time > - * queue_resume_timeout() is called. > - */ > - queue_suspend_timeout_locked(queue); > - > - /* If there's no job pending, we consider it progress to avoid a > - * spurious timeout if the timeout handler and the sync update > - * handler raced. > - */ > - progress = true; > - } else if (!list_empty(&done_jobs)) { > - queue_reset_timeout_locked(queue); > - progress = true; > - } > - spin_unlock(&queue->fence_ctx.lock); > dma_fence_end_signalling(cookie); > > list_for_each_entry_safe(job, job_tmp, &done_jobs, node) { > @@ -3346,9 +3342,8 @@ queue_run_job(struct drm_sched_job *sched_job) > job->ringbuf.end = job->ringbuf.start + (instrs.count * sizeof(u64)); > > panthor_job_get(&job->base); > - spin_lock(&queue->fence_ctx.lock); > - list_add_tail(&job->node, &queue->fence_ctx.in_flight_jobs); > - spin_unlock(&queue->fence_ctx.lock); > + scoped_guard(spinlock_irqsave, &queue->fence_ctx.lock) > + list_add_tail(&job->node, &queue->fence_ctx.in_flight_jobs); > > /* Make sure the ring buffer is updated before the INSERT > * register. > > -- > 2.54.0 > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯