From patchwork Wed Jun 16 08:26:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Christian_K=C3=B6nig?= X-Patchwork-Id: 461737 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15C92C49361 for ; Wed, 16 Jun 2021 08:27:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED5AF61359 for ; Wed, 16 Jun 2021 08:27:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231481AbhFPI3I (ORCPT ); Wed, 16 Jun 2021 04:29:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231468AbhFPI3I (ORCPT ); Wed, 16 Jun 2021 04:29:08 -0400 Received: from mail-ed1-x535.google.com (mail-ed1-x535.google.com [IPv6:2a00:1450:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C22AC06175F for ; Wed, 16 Jun 2021 01:27:01 -0700 (PDT) Received: by mail-ed1-x535.google.com with SMTP id s15so1512945edt.13 for ; Wed, 16 Jun 2021 01:27:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=bAUQPXbSkvT19k/XhsYs0cmL8Bgj7Ny0WAGbdIQQDHQ=; b=HxP9msOguWQ3QrHteS08n9aIIpmSVL0B0jsiRk4MJRbL7uofgZCKCoapjNf/2kiwdk 6Pb3l1Fc9AAZ/VCA3EHdMq5afGHtPvdGX2GUQdVJ0cKXTwGUpQJWgaUhzC0OOXYMGMs2 JbdyCuOMZpj8iV/WG+xz7zoV7SR38QcnQ9FBNgOimACUD0REuMD5SPbZyBucGx/w2Vpj gDk4kQBGE5BXa6AxcD7Q5IgG8RSE/JYkxUGv+IjtKZYbgR5iko6rgwhIsOid1X8SXd9o RfsKcaUNJD8eByyW4wemDj68FQ/qrYOOCUsR3cTTWq04Y1TPeEorHNbttrukQnr3h8k0 wXbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bAUQPXbSkvT19k/XhsYs0cmL8Bgj7Ny0WAGbdIQQDHQ=; b=rRAsqSQM9hqKy5+Bde7TU4o6/4XDDKrPokS0fxc0foWXM4CFOc17RMDH8oA5/bpjyW 4DloIlanXtYZ4vjtpGfADpvX2HGNproE7AvVjeHUg8zoF0ClZwMMyJGJ+wtGjqWdbNl0 axe9vTNH/NjuX+NspYMfBgKTFwdPqoR8x0riMmpjcRUrUOP0oOTqyC6jpuVPwnzGS9tW J4jypXGRWpYXssWUNThFgcMt+njsTGe+MJbpU3tn7y97xdn7aWcLnSYP6PCEjIL/N1ii aziaZZA/v+ndwVsVEyU5soRJedXO10WmzceJr63WXhSRqyrxpjjkzazXTdEFB1Rhublo CM3g== X-Gm-Message-State: AOAM530Abzf6On8zsBDaVfN05MrT6z5KuKJzfVfxUq/mbp8w/DDHq1Bq eXxb0YqHx/2qrslMJ2IL9ZY= X-Google-Smtp-Source: ABdhPJwuv9+M+3+hOg8rwV487BVcNbOkILX2dYfgDgwmpTEez1b9S9OjYK3Etjby1E1nrcMXGLnRog== X-Received: by 2002:aa7:cd77:: with SMTP id ca23mr2794529edb.259.1623832019927; Wed, 16 Jun 2021 01:26:59 -0700 (PDT) Received: from abel.fritz.box ([2a02:908:1252:fb60:8b88:17a4:582b:121f]) by smtp.gmail.com with ESMTPSA id v7sm1152639edx.38.2021.06.16.01.26.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Jun 2021 01:26:59 -0700 (PDT) From: "=?UTF-8?q?Christian=20K=C3=B6nig?=" X-Google-Original-From: =?utf-8?q?Christian_K=C3=B6nig?= To: daniel@ffwll.ch, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-media@vger.kernel.org, sumit.semwal@linaro.org Subject: [PATCH 1/7] dma-buf: add some more kerneldoc to dma_resv_add_shared_fence Date: Wed, 16 Jun 2021 10:26:49 +0200 Message-Id: <20210616082655.111001-2-christian.koenig@amd.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210616082655.111001-1-christian.koenig@amd.com> References: <20210616082655.111001-1-christian.koenig@amd.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Explicitly document that code can't assume that shared fences signal after the exclusive fence. Signed-off-by: Christian König --- drivers/dma-buf/dma-resv.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index f26c71747d43..4ab02b6c387a 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -235,7 +235,10 @@ EXPORT_SYMBOL(dma_resv_reset_shared_max); * @fence: the shared fence to add * * Add a fence to a shared slot, obj->lock must be held, and - * dma_resv_reserve_shared() has been called. + * dma_resv_reserve_shared() has been called. The shared fences can signal in + * any order and there is especially no guarantee that shared fences signal + * after the exclusive one. Code relying on any signaling order is broken and + * needs to be fixed. */ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence) {