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 2D7A5C35254 for ; Wed, 5 Feb 2020 11:59:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9EE3218AC for ; Wed, 5 Feb 2020 11:59:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580903952; bh=e2wpDkaca94WD5/bWbgprPG9Vj1e3ghMDbeVWFnC7pE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=g+LDPyTZorgng9oaQFImzYXm8zt/g9nP1cdbzTpNlQNltYMHpQ2NvjlksqeodeEC8 CIxkNIF3iR50se5azmr3dlevJ4mzKrnmQLgebA7lwSOikC2RjsWVq0JXoA0jUXZgp1 uZA3I2DNBVWZqJX+qXn7+uyxC7lU5ecqSbfSSlqk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726953AbgBEL7L (ORCPT ); Wed, 5 Feb 2020 06:59:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:47700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726386AbgBEL7L (ORCPT ); Wed, 5 Feb 2020 06:59:11 -0500 Received: from localhost (unknown [122.178.239.37]) (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 E1CB4217F4; Wed, 5 Feb 2020 11:59:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580903950; bh=e2wpDkaca94WD5/bWbgprPG9Vj1e3ghMDbeVWFnC7pE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i+T2aI18PEwzwPN66edZzxNyr1exqENkEPYyPzuqFmOkbeMADS1niFPCUm4eumM4g tHOY+IUkpDB9RbEY+KuYCn1gfEKlXNMdbfxIViOy+lN15E3W7rUs37XcfTcFVANG+U 0YAObt+d/CnW2Em9D1vT97V2wrWlREYxu5MB8UnM= Date: Wed, 5 Feb 2020 17:29:06 +0530 From: Vinod Koul To: Peter Ujfalusi Cc: Andy Shevchenko , dmaengine , Linux Kernel Mailing List , Dan Williams Subject: Re: [PATCH 0/3] dmaengine: Stear users towards dma_request_slave_chan() Message-ID: <20200205115906.GF2618@vkoul-mobl> References: <20200203101806.2441-1-peter.ujfalusi@ti.com> <20200204062118.GS2841@vkoul-mobl> <20200205044352.GC2618@vkoul-mobl> <13dcf3d9-06ca-d793-525d-12f6d7cd27c1@ti.com> <20200205113155.GE2618@vkoul-mobl> <7b8d9ab2-1734-d54b-ab6e-b620866ce0ce@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7b8d9ab2-1734-d54b-ab6e-b620866ce0ce@ti.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 05-02-20, 13:56, Peter Ujfalusi wrote: > Hi Vinod, > > On 05/02/2020 13.31, Vinod Koul wrote: > >> Looking at the commit which added it and I still don't get the point. > >> If any of the channel is in use then we should not allow the DMA driver > >> to go away at all. > > > > Not really, if the device is already gone, we cant do much about it. We > > have to handle that gracefully rather than oopsing > > Ah, I have not thought about that. True. > > > The important part is that the device is gone. Think about a device on > > PCI card which is yanked off or a USB device unplugged. Device is > > already gone, you can't communicate with it anymore. So all we can do is > > handle the condition and exit, hence the new method to let driver know. > > But for most devices this is not applicable, I also wondered what should > I do in order to silence the print. Just add an empty device_release? I will send a patch removing this before we hit release :) so nothing to be done unless you have a hotpluggable device then would be good to add this. Thanks -- ~Vinod