From nobody Thu Oct 2 20:46:44 2025 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 60870329F2B for ; Thu, 11 Sep 2025 22:00:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757628051; cv=none; b=FQZi8t7vWMg7UipF9+Ibtc3Y0KICRzmvgSEwmpIyjH874Jjf8JEbWqGSfzjNE5xQQjZ5giCmlq/b61j832/ztG3+uq8xpWvFSm3MfPzOiburG5DKHG0bNSTGShKToTyyJzcm+HXEX/C7vHc+L4yOZbcRFC+9i9KfuZFTPqwYpx8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757628051; c=relaxed/simple; bh=BNKjLiMwo7xVG7m5N0r9qNaKtaldo4UnpNJT9EOqrg0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ZCHkvBSA4iYkEkOdgG7vH5pvIEMCZJdrneqJxWrb9OMInKohmccMsxCHzwtLJz1+1pXmUJw47U9EC1gUa0ZFrA9UKRyCZI/Q8tZf533Nu6VlH+mAZlsvRwuIKn6/hpTD7OraZYlpv4EIXtVt5c4IDtvaQFBfWfZJ6lzBtdHYZ9I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from dude02.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::28]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1uwpLU-0005sG-Me; Fri, 12 Sep 2025 00:00:48 +0200 From: Marco Felsch Date: Fri, 12 Sep 2025 00:00:42 +0200 Subject: [PATCH 2/2] dmaengine: imx-sdma: fix supplier/consumer dependency handling Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250912-v6-16-topic-dma-devlink-v1-2-4debc2fbf901@pengutronix.de> References: <20250912-v6-16-topic-dma-devlink-v1-0-4debc2fbf901@pengutronix.de> In-Reply-To: <20250912-v6-16-topic-dma-devlink-v1-0-4debc2fbf901@pengutronix.de> To: Vinod Koul , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Jiada Wang , Frank Li Cc: dmaengine@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Marco Felsch X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:1101:1d::28 X-SA-Exim-Mail-From: m.felsch@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org The whole driver was converted to the devm APIs except for this last for-loop. This loop is buggy due to three reasons: 1) It removes the channels without removing the users first. This can lead to very bad situations. 2) The loop starts at 0 and which is channel0 which is a special control channel not registered via vchan_init(). Therefore the remove() always Oops because of NULL pointer exception. 3) sdma_free_chan_resources() disable the clks unconditional without checking if the clks are enabled. This is done for all MAX_DMA_CHANNELS which hang the system if there is at least one unused channel. The first issue is fixed by making use of the dmaengine devlink support. The second issue is fixed by not doing anything on channel0. The last issue is also fixed by the devlink support because during the consumer teardown phase each requested channel is dropped accordingly so the dmaengine driver doesn't need to this. To sum-up, all issues are fixed by dropping the .remove() callback and let the frameworks do their job. Reviewed-by: Frank Li Signed-off-by: Marco Felsch --- drivers/dma/imx-sdma.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index d4430e6e56deda7de3538e42af7987a456957b43..a11317c8827297d1d6b8ddc0254= ecf549e486001 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -2393,6 +2393,7 @@ static int sdma_probe(struct platform_device *pdev) sdma->dma_device.device_prep_dma_memcpy =3D sdma_prep_memcpy; sdma->dma_device.device_issue_pending =3D sdma_issue_pending; sdma->dma_device.copy_align =3D 2; + sdma->dma_device.create_devlink =3D true; dma_set_max_seg_size(sdma->dma_device.dev, SDMA_BD_MAX_CNT); =20 platform_set_drvdata(pdev, sdma); @@ -2432,25 +2433,11 @@ static int sdma_probe(struct platform_device *pdev) return 0; } =20 -static void sdma_remove(struct platform_device *pdev) -{ - struct sdma_engine *sdma =3D platform_get_drvdata(pdev); - int i; - - /* Kill the tasklet */ - for (i =3D 0; i < MAX_DMA_CHANNELS; i++) { - struct sdma_channel *sdmac =3D &sdma->channel[i]; - - sdma_free_chan_resources(&sdmac->vc.chan); - } -} - static struct platform_driver sdma_driver =3D { .driver =3D { .name =3D "imx-sdma", .of_match_table =3D sdma_dt_ids, }, - .remove =3D sdma_remove, .probe =3D sdma_probe, }; =20 --=20 2.47.3