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 17009C32771 for ; Mon, 27 Jan 2020 05:08:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2654214DB for ; Mon, 27 Jan 2020 05:08:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580101719; bh=sh4gpOdiYLotpOkB88cXx9+mmjB24ViBFWqv5LExZ4k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Xy72AW/T2y+JPtytkBIEA6g990SRHk7pPmbXiy2yXQJvyTJzASRyLpzbbvGcIzLUr msqRk6cAbI6y6VYHCTIaum0RD079K736YWAuMnyfV4XPe6TBBdZze0Y132LIs7xC2m ggdo/Cm13bGU2+vjPsNLAmVf9vExiZadP3PMUXuo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725830AbgA0FIf (ORCPT ); Mon, 27 Jan 2020 00:08:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:57590 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725308AbgA0FIe (ORCPT ); Mon, 27 Jan 2020 00:08:34 -0500 Received: from localhost (unknown [122.181.201.159]) (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 9E87720716; Mon, 27 Jan 2020 05:08:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580101714; bh=sh4gpOdiYLotpOkB88cXx9+mmjB24ViBFWqv5LExZ4k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Wx8aPOpTS+Kb2Sy5Wmlm+U+6x5esBaImXY6fF8DDRxJiOuDQ2Gthx9hRn5n1quRzx hnI7vjTugmK/dGJ8BV7fRkGx9TGps7+BxXI0/Ho2D7B7MUdXVpDw1QOr8OUUxTnVgM FGMR+Aml/vS6dPUaDOXay9A0w9g3UwsPu1iErjGY= Date: Mon, 27 Jan 2020 10:38:28 +0530 From: Vinod Koul To: Peter Ujfalusi Cc: Geert Uytterhoeven , Dan Williams , dmaengine@vger.kernel.org, Linux-Renesas , Linux Kernel Mailing List Subject: Re: [PATCH v2] dmaengine: Create symlinks between DMA channels and slaves Message-ID: <20200127050828.GH2841@vkoul-mobl> References: <20200117153056.31363-1-geert+renesas@glider.be> <1cdc4f71-f365-8c9e-4634-408c59e6a3f9@ti.com> <20200122094002.GS2841@vkoul-mobl> <20200124061359.GF2841@vkoul-mobl> <876eb72f-db74-86b5-5f2c-7fc9a5252421@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <876eb72f-db74-86b5-5f2c-7fc9a5252421@ti.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 24-01-20, 09:31, Peter Ujfalusi wrote: > Vinod, Geert, > > On 24/01/2020 8.13, Vinod Koul wrote: > > On 22-01-20, 15:10, Vinod Koul wrote: > > > >> I like the idea of adding this in debugfs and giving more info, I would > >> actually love to add bytes_transferred and few more info (descriptors > >> submitted etc) to it... > >> > >>>> This way we will have all the information in one place, easy to look up > >>>> and you don't need to manage symlinks dynamically, just check all > >>>> channels if they have slave_device/name when they are in_use (in_use w/o > >>>> slave_device is 'non slave') > >>>> > >>>> Some drivers are requesting and releasing the DMA channel per transfer > >>>> or when they are opened/closed or other variations. > >>>> > >>>>> What do other people think? > >>> > >>> Vinod: do you have some guidance for your minions? ;-) > >> > >> > >> That said, I am not against merging this patch while we add more > >> (debugfs)... So do my minions agree or they have better ideas :-) > > > > So no new ideas, I am going to apply this and queue for 5.6, something > > is better than nothing. > > My only issue with the symlink is that it is created/removed on some > setups quite frequently as they request/release channel per transfer or > open/close. > It might be a small hit in performance, but it is going to be for them. > > > And I am looking forward for debugfs to give better picture, volunteers? > > Well, I still feel that the debugfs can give better view in one place > and in production it can be disabled to save few bytes per channel and > code is not complied in. > > If we have the debugfs we can remove some of the sysfs devices files > probably. Sure I dont mind if we move to something better :) We went from zero to something and can do better! Thanks -- ~Vinod