From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-247.mta1.migadu.com [95.215.58.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5E8E84DA9C3 for ; Mon, 28 Sep 2026 19:28:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.247 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790623740; cv=none; b=nZMerqPTv6joAA8bU+ho6nQ/qJVV8pwr4DJdHqvVW63YtUB2vwN3mIOkQw1xqSEeZsyCCUO50HiGbtc4phWnEOrNG1X8VeYaQc7GbXMIp6DEYiTJ5atw8gVCKppZnf5kdoh/QJuIowE1XxIO9xZg40wdfhG70xuOB2zGrjcIt78= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790623740; c=relaxed/simple; bh=6GdeS5J1nAEzAADIZpXQl1fwy/uaoTDl+7jyHikSKZc=; h=Mime-Version:Content-Type:Date:Message-Id:From:To:Cc:Subject: References:In-Reply-To; b=cbi7LHmeXg+fOYqwXkf6OTLckGvd2iE86ivg1pOgcN9gbfLRc4VwI5o6ztl+N0bwxdM8Tcn/b1iKS9aHJCQXIU2lyVDbRS7DdY4fFQ8gscTb5DxCeBwZJazzWCkswzLmv60jIFRtAqCRyA5Ngl/qiJLRmuLvUzhjL3qRMO8Ty44= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=cknow-tech.com; spf=pass smtp.mailfrom=cknow-tech.com; dkim=pass (2048-bit key) header.d=cknow-tech.com header.i=@cknow-tech.com header.b=YcUpAmOf; arc=none smtp.client-ip=95.215.58.247 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=cknow-tech.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cknow-tech.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cknow-tech.com header.i=@cknow-tech.com header.b="YcUpAmOf" X-Envelope-To: linux-media@vger.kernel.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=1790623731; v=1; x=1791228531; b=YcUpAmOfqJTgUK4bL0o44Iu2boLVx6GhQYzm07LXlkz2rycFcrmJ22DcFH84h/YoWVOl+sDP kriEwplZF7XaDfIH9/VV5f+LxhtCUwIoOUWmtSVhCfRerSXsfH7DBfjEK56FLCICOndgGx0shE0 +AEx7x5L5NjgeAeYR2/3c7qqTpajrl83ow6UqyFfln+DwhIdLr2zS8ZDsZ8btojS/sJGaE3F/4A WsPcoTptlXR2F/CDYGhcQ+Fwvp9AT0vVi4sJQEa/yc9X3NKtN2GyNhyZ9z/XId/v9/WVUQof25g lR1GAA+cNlqpzkiSgqKi8U85tTkFN/34zzYPB9FVCfVMg== X-Envelope-To: linux-media@vger.kernel.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 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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> 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