From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83E44230D0F; Mon, 10 Mar 2025 17:10:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741626619; cv=none; b=IgMQOg5ORU0jkXpQNJ5zlEbL9aK8oAeeQPUdfjE0T6rW5XU9XIcAv2rjbGyO6NqBfasopvaVs7tpS5gPLi7rNARq3E71FoA5mvfqnSYeetGy6qdMfgQlL+5iLc7Beo2RsKtNpUqhUkYNkgg6sR2U6T9n5JWBv24Q8Vx72sF5Ebw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741626619; c=relaxed/simple; bh=f2ebQUAlynQptLK3/1knvtDxytwkzEC5HKJpG0wFKRM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=d7R0yDdUxAkNElGjVT8RZ7HrVQFtR0dMIkEhFqNjDgEvpKOS9iX29P7k88s7mAjo+TDmeXgMvsvGTUXKgnVOHrL8+O/6ALoaIOxsVAqLHAROZmDX5jEbYMVj0PR/WlzyOiwoA/41hHlItLpfny0m/mJZpaWiL4UpDyWHVkICzuo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZFItDxZa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZFItDxZa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE1B2C4CEE5; Mon, 10 Mar 2025 17:10:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741626619; bh=f2ebQUAlynQptLK3/1knvtDxytwkzEC5HKJpG0wFKRM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZFItDxZaO9Y7iGnBzmmF6anBrbk/++1desvOesYEd5RYdUA3shul0dpzjzb7uKLJ/ iryf35UpaDreLCOgZV5BBRMNYg1po9Ax2cqlv9zz+QweJ3i2Bu4kCtXT3U0PvC4eEK z/6fwCRGpXOF3PW9uBiOerzK2bDkJfhSg005Th3M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Brendan King , Matt Coster Subject: [PATCH 6.13 037/207] drm/imagination: avoid deadlock on fence release Date: Mon, 10 Mar 2025 18:03:50 +0100 Message-ID: <20250310170449.249051613@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170447.729440535@linuxfoundation.org> References: <20250310170447.729440535@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Brendan King commit df1a1ed5e1bdd9cc13148e0e5549f5ebcf76cf13 upstream. Do scheduler queue fence release processing on a workqueue, rather than in the release function itself. Fixes deadlock issues such as the following: [ 607.400437] ============================================ [ 607.405755] WARNING: possible recursive locking detected [ 607.415500] -------------------------------------------- [ 607.420817] weston:zfq0/24149 is trying to acquire lock: [ 607.426131] ffff000017d041a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: pvr_gem_object_vunmap+0x40/0xc0 [powervr] [ 607.436728] but task is already holding lock: [ 607.442554] ffff000017d105a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: dma_buf_ioctl+0x250/0x554 [ 607.451727] other info that might help us debug this: [ 607.458245] Possible unsafe locking scenario: [ 607.464155] CPU0 [ 607.466601] ---- [ 607.469044] lock(reservation_ww_class_mutex); [ 607.473584] lock(reservation_ww_class_mutex); [ 607.478114] *** DEADLOCK *** Cc: stable@vger.kernel.org Fixes: eaf01ee5ba28 ("drm/imagination: Implement job submission and scheduling") Signed-off-by: Brendan King Reviewed-by: Matt Coster Link: https://patchwork.freedesktop.org/patch/msgid/20250226-fence-release-deadlock-v2-1-6fed2fc1fe88@imgtec.com Signed-off-by: Matt Coster Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/imagination/pvr_queue.c | 13 +++++++++++-- drivers/gpu/drm/imagination/pvr_queue.h | 4 ++++ 2 files changed, 15 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/imagination/pvr_queue.c +++ b/drivers/gpu/drm/imagination/pvr_queue.c @@ -109,12 +109,20 @@ pvr_queue_fence_get_driver_name(struct d return PVR_DRIVER_NAME; } +static void pvr_queue_fence_release_work(struct work_struct *w) +{ + struct pvr_queue_fence *fence = container_of(w, struct pvr_queue_fence, release_work); + + pvr_context_put(fence->queue->ctx); + dma_fence_free(&fence->base); +} + static void pvr_queue_fence_release(struct dma_fence *f) { struct pvr_queue_fence *fence = container_of(f, struct pvr_queue_fence, base); + struct pvr_device *pvr_dev = fence->queue->ctx->pvr_dev; - pvr_context_put(fence->queue->ctx); - dma_fence_free(f); + queue_work(pvr_dev->sched_wq, &fence->release_work); } static const char * @@ -268,6 +276,7 @@ pvr_queue_fence_init(struct dma_fence *f pvr_context_get(queue->ctx); fence->queue = queue; + INIT_WORK(&fence->release_work, pvr_queue_fence_release_work); dma_fence_init(&fence->base, fence_ops, &fence_ctx->lock, fence_ctx->id, atomic_inc_return(&fence_ctx->seqno)); --- a/drivers/gpu/drm/imagination/pvr_queue.h +++ b/drivers/gpu/drm/imagination/pvr_queue.h @@ -5,6 +5,7 @@ #define PVR_QUEUE_H #include +#include #include "pvr_cccb.h" #include "pvr_device.h" @@ -63,6 +64,9 @@ struct pvr_queue_fence { /** @queue: Queue that created this fence. */ struct pvr_queue *queue; + + /** @release_work: Fence release work structure. */ + struct work_struct release_work; }; /**