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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A65F7CA5FA3 for ; Mon, 28 Sep 2026 19:35:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1035510EBB4; Mon, 28 Sep 2026 19:35:11 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=cknow-tech.com header.i=@cknow-tech.com header.b="LIIrUs07"; dkim-atps=neutral Received: from mta1.migadu.com (out-48.mta1.migadu.com [95.215.58.48]) by gabe.freedesktop.org (Postfix) with ESMTPS id A975710EBB4 for ; Mon, 28 Sep 2026 19:35:07 +0000 (UTC) X-Envelope-To: dri-devel@lists.freedesktop.org DKIM-Signature: a=rsa-sha256; bh=6GdeS5J1nAEzAADIZpXQl1fwy/uaoTDl+7jyHikSKZc=; c=simple/simple; d=cknow-tech.com; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790624105; v=1; x=1791228905; b=LIIrUs07PDS31P3GtcKlFbpeJkkJDwMH9Eiri2PUlYs4voOm4sgXuJOYt0i1aEyfj9Lu1dy/ nMhpULR5eEje6W5Bf9CBxLmxwQbHLbDHn9UDbKOC91XMVsW83Nmn1ZIf4wtF/l9e03QiDmG86eS /ZBfHorgVd2A0XaZthh9CyANq0Fap0MN6JN9NkAjSq+dBLsLimJ2Cw4asZVdA5VNbjpuUzz0Xwo kzTpcChy8TA/I7ufo3g2DXizZZDABX6cF9jTtiae7x5bGlH5cZuhpHReu8YzTbkxBMQT7HJwoxF HCZrJZW764GMn6l1e4slkj2kBagZw7R/gl3y6utVK6bJg== X-Envelope-To: dri-devel@lists.freedesktop.org Received: by smtp.migadu.com with ESMTPS id a3187ec75891e86d; Mon, 28 Sep 2026 19:28:51 +0000 X-Mizu-Trace-ID: a3187ec75891e86d X-Migadu-Flow: FLOW_OUT Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 28 Sep 2026 21:28:47 +0200 Message-Id: From: "Diederik de Haas" To: "Karl Mehltretter" , "Sumit Semwal" , =?utf-8?q?Christian_K=C3=B6nig?= Cc: , , , "Sandy Huang" , =?utf-8?q?Heiko_St=C3=BCbner?= , "Andy Yan" , , "Detlev Casanova" , "Jonas Karlman" Subject: Re: [PATCH] dma-buf: Make DMABUF_DEBUG default to y on DEBUG_KERNEL kernels X-Mailer: aerc 0.22.0-31-g5c1c510d2b65 References: <20260907020015.24719-1-kmehltretter@gmail.com> In-Reply-To: <20260907020015.24719-1-kmehltretter@gmail.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 Mon Sep 7, 2026 at 4:00 AM CEST, Karl Mehltretter wrote: > Commit 646013f513f3 ("dma-buf: enable DMABUF_DEBUG by default on DEBUG > kernels") changed the default of DMABUF_DEBUG to "y if DEBUG", but no > Kconfig symbol DEBUG exists, so the option has had no default since. > > Use DEBUG_KERNEL, the Kconfig symbol for a debug kernel. I wondered why since 7.3-rc4 when playing videos I got a WHOLE lot of the following error messages, which weren't there with 7.3-rc3: [drm:rockchip_gem_iommu_map [rockchipdrm]] *ERROR* failed to map buffer: = size=3D0 request_size=3D3956736 [drm:rockchip_gem_prime_import_sg_table [rockchipdrm]] *ERROR* failed to = import sg table: -12 Both come from ``drivers/gpu/drm/rockchip/rockchip_drm_gem.c``. The value of request_size varies sometimes; I see ``request_size=3D8294400`= ` the most. When playing a video (with mpv with v4l2request functionality, bu= t I think that doesn't matter), I see a whole bunch of these errors and then it stays 'silent', but I get another stream of them when I resize the windo= w (ie I'm toggling between windowed and full-screen). It doesn't take long before dmesg only consists of these errors. The 'playing video' is likely important; when I just start sway I don't see those errors. It's only when I start a video that those pop up. My kernel (config) is based on Debian's and that has ``DEBUG_KERNEL=3Dy`` a= t least since 2008 and due to this patch/commit, ``DMABUF_DEBUG`` got turned = on. When I explicitly disable ``DMABUF_DEBUG``, I no longer see those errors. Whether that fixes or just hides a problem, I'll leave that for others to decide. > Fixes: 646013f513f3 ("dma-buf: enable DMABUF_DEBUG by default on DEBUG ke= rnels") > Assisted-by: LLM > Signed-off-by: Karl Mehltretter > --- > This enables the dma-buf debug checks on every CONFIG_DEBUG_KERNEL > configuration, which is what 646013f513f3 set out to do. If that is too > broad today, the alternative is to restore the previous > "default y if DMA_API_DEBUG". My 0.02: That change landed in 7.0-rc1 albeit it didn't have the effect it intended to achieve. An -rc1 version seems like the right version to land such a cha= nge. I'm not in favor of this just popping up in 7.3-rc4 while -rc3 did NOT have that affect. With an -rc1 you'd expect major changes, but in this case I accidentally stumbled upon it while trying out something else. Cheers, Diederik > drivers/dma-buf/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig > index 7efc0f0d0712..e4f078a326a4 100644 > --- a/drivers/dma-buf/Kconfig > +++ b/drivers/dma-buf/Kconfig > @@ -43,7 +43,7 @@ config UDMABUF > config DMABUF_DEBUG > bool "DMA-BUF debug checks" > depends on DMA_SHARED_BUFFER > - default y if DEBUG > + default y if DEBUG_KERNEL > help > This option enables additional checks for DMA-BUF importers and > exporters. Specifically it validates that importers do not peek at th= e > > base-commit: 986c24e0fe44f844b44d365b71ce831947f50298