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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 78860C2D0C0 for ; Mon, 23 Dec 2019 07:51:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4DB6120709 for ; Mon, 23 Dec 2019 07:51:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577087509; bh=oW2xxtRpv875kyNQhyqk3EKF34qFvDngT6PxUmGhQvg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=pHPqKIpia2rchEv+VELP9CwEHEJM//3PP9Zhjzy3vAgdB0JJ79qh2vjJmiztNwOTU IRFR8eIyQD8xY4lw+sTi1/L2T8C+KWxloX1LBnqylnHoYWmlJe94L/twL0Vf/GK6s1 qF6l5GHpkdvkc/yt6OsE3RxrjLNbBAjB0RHWBnSE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725867AbfLWHvt (ORCPT ); Mon, 23 Dec 2019 02:51:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:57110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725810AbfLWHvs (ORCPT ); Mon, 23 Dec 2019 02:51:48 -0500 Received: from localhost (unknown [223.226.34.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7EA992081E; Mon, 23 Dec 2019 07:51:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577087508; bh=oW2xxtRpv875kyNQhyqk3EKF34qFvDngT6PxUmGhQvg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AbNUWnyGzlxuavrEQZEjE+QUHOcaT4ZawKBP2KmIaMgFxiRvIm6LxqRbQDHzbkVMW N+Ygclbe51F/AwjA2e4Ps6keyWe+IjCnmimn09dsHtOvou3cQblRN05+vhoadF7NJ8 oZV8LXmZRW7JhOb4NQUL1+MxVjAxgs4d9c5gSBP8= Date: Mon, 23 Dec 2019 13:21:43 +0530 From: Vinod Koul To: John Stultz Cc: lkml , Dan Williams , ryan@edited.us, aserbinski@gmail.com, dmaengine@vger.kernel.org Subject: Re: [PATCH] k3dma: Avoid null pointer traversal Message-ID: <20191223075143.GC2536@vkoul-mobl> References: <20191218190906.6641-1-john.stultz@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191218190906.6641-1-john.stultz@linaro.org> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 18-12-19, 19:09, John Stultz wrote: > In some cases we seem to submit two transactions in a row, which > causes us to lose track of the first. If we then cancel the > request, we may still get an interrupt, which traverses a null > ds_run value. > > So try to avoid starting a new transaction if the ds_run value > is set. > > While this patch avoids the null pointer crash, I've had some > reports of the k3dma driver still getting confused, which > suggests the ds_run/ds_done value handling still isn't quite > right. However, I've not run into an issue recently with it > so I think this patch is worth pushing upstream to avoid the > crash. Applied after adding dmaengine tag, thanks -- ~Vinod