From mboxrd@z Thu Jan 1 00:00:00 1970 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 D441EC433EC for ; Mon, 22 Mar 2021 12:38:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B825D60C3E for ; Mon, 22 Mar 2021 12:38:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231614AbhCVMik (ORCPT ); Mon, 22 Mar 2021 08:38:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:56226 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231643AbhCVMeC (ORCPT ); Mon, 22 Mar 2021 08:34:02 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 29C2A6199F; Mon, 22 Mar 2021 12:34:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1616416442; bh=N40+fZ3YNOp4uPZiFC1mNZfL5mBEIhSqyr+K9hCmHuI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qsw8DBfkw37M/szzFaLZn4B2aGR+/8kYFndz3tp2sgdUT3CaYQL1zfQ+MuAr2d/r8 k67dFxLrGxBlcoavJXVqbITCreCEoGZEvQq0gbDo6Qk/oJU6l/6f1R1TET3uLvvy4X lVGaATcuzPRdxNHJo6PbKb2ceXZaHPvzCcFF4f2E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Huang Rui , =?UTF-8?q?Christian=20K=C3=B6nig?= , Daniel Vetter , Sasha Levin Subject: [PATCH 5.11 073/120] drm/ttm: Warn on pinning without holding a reference Date: Mon, 22 Mar 2021 13:27:36 +0100 Message-Id: <20210322121932.109281887@linuxfoundation.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210322121929.669628946@linuxfoundation.org> References: <20210322121929.669628946@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Vetter [ Upstream commit 57fcd550eb15bce14a7154736379dfd4ed60ae81 ] Not technically a problem for ttm, but very likely a driver bug and pretty big time confusing for reviewing code. So warn about it, both at cleanup time (so we catch these for sure) and at pin/unpin time (so we know who's the culprit). Reviewed-by: Huang Rui Reviewed-by: Christian König Signed-off-by: Daniel Vetter Cc: Christian Koenig Cc: Huang Rui Link: https://patchwork.freedesktop.org/patch/msgid/20201028113120.3641237-1-daniel.vetter@ffwll.ch Signed-off-by: Sasha Levin --- drivers/gpu/drm/ttm/ttm_bo.c | 2 +- include/drm/ttm/ttm_bo_api.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 22073e77fdf9..a76eb2c14e8c 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -514,7 +514,7 @@ static void ttm_bo_release(struct kref *kref) * shrinkers, now that they are queued for * destruction. */ - if (bo->pin_count) { + if (WARN_ON(bo->pin_count)) { bo->pin_count = 0; ttm_bo_del_from_lru(bo); ttm_bo_add_mem_to_lru(bo, &bo->mem); diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 2564e66e67d7..79b9367e0ffd 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -600,6 +600,7 @@ static inline bool ttm_bo_uses_embedded_gem_object(struct ttm_buffer_object *bo) static inline void ttm_bo_pin(struct ttm_buffer_object *bo) { dma_resv_assert_held(bo->base.resv); + WARN_ON_ONCE(!kref_read(&bo->kref)); ++bo->pin_count; } @@ -613,6 +614,7 @@ static inline void ttm_bo_unpin(struct ttm_buffer_object *bo) { dma_resv_assert_held(bo->base.resv); WARN_ON_ONCE(!bo->pin_count); + WARN_ON_ONCE(!kref_read(&bo->kref)); --bo->pin_count; } -- 2.30.1