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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 B1966C00144 for ; Fri, 29 Jul 2022 11:01:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-ID:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=ZINgIH7hASdSjeKE7gsQYubSJVm0zM+xry3+znUnMa8=; b=1TFwEJSZrgcyYIsXGsZ61ZNney 19pkZaJh5RPtqHfM0OuNTfqjc22GpW+EVhtUNsAsoTq9JtOpP/lw+/IccPEKnkSzMiU7HQNVVpyrZ Aur/f+JuQafDUPgW+VS6QHKmwK2sZU8znYo4LZSQRK9GQqS0CL0uXAmah60h3vjfK+VoTfRnhxqRP 7zeGIVJ2+ZhE9//luKaiMrDsPJoSeaS08x5DPmBUozPY8qGjJcvstnktdveRKdl+KH3MVGegx8uj/ EcWdfJiGoTPolRGwdENKUURArq1dlyoXp1KvVfG7svl6f4kYSFB+XEMaACuZCyoV71gaVqIxcw2l+ qjuYuL+Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oHNj7-004HTy-9Y; Fri, 29 Jul 2022 11:00:17 +0000 Received: from mail.thorsis.com ([92.198.35.195]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oHNj4-004HOQ-GX; Fri, 29 Jul 2022 11:00:16 +0000 From: Alexander Dahl To: linux-mtd@lists.infradead.org Subject: Re: [PATCH] mtd: rawnand: atmel: Unmap streaming DMA mappings Date: Fri, 29 Jul 2022 12:59:55 +0200 Message-ID: <2099405.mp5hVA6q5l@ada> In-Reply-To: <20220728074014.145406-1-tudor.ambarus@microchip.com> References: <20220728074014.145406-1-tudor.ambarus@microchip.com> X-Clacks-Overhead: GNU Terry Pratchett X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220729_040014_760932_92650FB2 X-CRM114-Status: GOOD ( 12.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alexandre.belloni@bootlin.com, linux-kernel@vger.kernel.org, vigneshr@ti.com, Tudor Ambarus , richard@nod.at, bbrezillon@kernel.org, stable@vger.kernel.org, claudiu.beznea@microchip.com, miquel.raynal@bootlin.com, peda@axentia.se, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello Tudor, Am Donnerstag, 28. Juli 2022, 09:40:14 CEST schrieb Tudor Ambarus: > Every dma_map_single() call should have its dma_unmap_single() counterpart, > because the DMA address space is a shared resource and one could render the > machine unusable by consuming all DMA addresses. > > Cc: stable@vger.kernel.org > Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver") > Signed-off-by: Tudor Ambarus > --- > drivers/mtd/nand/raw/atmel/nand-controller.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c > b/drivers/mtd/nand/raw/atmel/nand-controller.c index > 6ef14442c71a..330d2dafdd2d 100644 > --- a/drivers/mtd/nand/raw/atmel/nand-controller.c > +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c > @@ -405,6 +405,7 @@ static int atmel_nand_dma_transfer(struct > atmel_nand_controller *nc, > > dma_async_issue_pending(nc->dmac); > wait_for_completion(&finished); > + dma_unmap_single(nc->dev, buf_dma, len, dir); > > return 0; Acked-by: Alexander Dahl After studying https://www.kernel.org/doc/html/latest/core-api/dma-api-howto.html this seems like the correct thing to do to me. I was made aware of this patch in IRC, after discussing a strange lzo decompression and/or page reading error with Richard after upgrading from kernel v5.2.21-rt13 to v5.15.49-rt47. Now testing this on top of 5.15.49-rt47 on two boards, both with Microchip sama5d27c 128MiB SiP and Spansion S34ML02G1 raw nand flash. Will report later. Thanks and greets Alex _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel