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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 3D332C04AA5 for ; Mon, 15 Oct 2018 14:01:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03FD220652 for ; Mon, 15 Oct 2018 14:01:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="aRd+94Mv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 03FD220652 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726615AbeJOVqp (ORCPT ); Mon, 15 Oct 2018 17:46:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:53080 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726421AbeJOVqp (ORCPT ); Mon, 15 Oct 2018 17:46:45 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (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 2D90120652; Mon, 15 Oct 2018 14:01:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539612080; bh=b68ghKJ0HmCV0lPxHK5DXXgD18fR/iBQ+X1bapRSZ6A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aRd+94MvKeVlGSFlxnuo8PfPVYJPY00GsF/7NAHV23TqGXXuLyo7oPGHtnrN8gHKN PqzimOy3KJUF/q5m/8rX6avueR2+chAgFvKVX8bQsexiNzjJpT4by+duFDTegbvDk+ zXSv+pRZuk/F4xJ4ByTFptRRFqhl6aAKAe87Bkp8= Date: Mon, 15 Oct 2018 16:01:18 +0200 From: Greg KH To: Fabien Lahoudere Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: Re: [PATCH v3 1/1] serial: imx - Add dma buffer confugration via sysfs Message-ID: <20181015140118.GA16234@kroah.com> References: <1539249903-6316-1-git-send-email-fabien.lahoudere@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1539249903-6316-1-git-send-email-fabien.lahoudere@collabora.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 11, 2018 at 11:25:03AM +0200, Fabien Lahoudere wrote: > In order to optimize serial communication on imx53 and imx6, we may > need to tweak DMA period and buffer length per period. Why can you not just automatically determine this information? What is userspace going to know that the kernel can not just learn now? Having tunables is nice, but it is even better to not need them at all. thanks, greg k-h