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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, 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 1E82FC43441 for ; Fri, 23 Nov 2018 00:26:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4CD220813 for ; Fri, 23 Nov 2018 00:26:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="ciRAm0bY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D4CD220813 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk 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 S2439174AbeKWLIC (ORCPT ); Fri, 23 Nov 2018 06:08:02 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:42792 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405050AbeKWLIC (ORCPT ); Fri, 23 Nov 2018 06:08:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2014; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=P8eN/TfoExd2pqRphUlEH0sS3BJPdvFIkq5RPGepous=; b=ciRAm0bY97OyZirsVNQmeQZDj 89cpwSWWHIwkUlBfCHE6+rpLTnPzVyCg3OfzyijC1EkaPSzgvkJYLYsGIQ7hItN2iU8YyIUH5agXb 3joPjCO7ZnfrCZIpGCYa87HxfeyZ+kBYUZ5CJzv6wrMLTHwqNrvknQ0beaETi0B0/kDQo=; Received: from n2100.armlinux.org.uk ([2002:4e20:1eda:1:214:fdff:fe10:4f86]:45848) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1gPzIB-0004t7-Hx; Fri, 23 Nov 2018 00:25:55 +0000 Received: from linux by n2100.armlinux.org.uk with local (Exim 4.90_1) (envelope-from ) id 1gPzI7-0007xU-Oz; Fri, 23 Nov 2018 00:25:51 +0000 Date: Fri, 23 Nov 2018 00:25:49 +0000 From: Russell King - ARM Linux To: Aaro Koskinen Cc: Peter Ujfalusi , vkoul@kernel.org, dan.j.williams@intel.com, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, tony@atomide.com, linux-omap@vger.kernel.org Subject: Re: [PATCH] dmaengine: ti: omap-dma: Configure LCH_TYPE for OMAP1 Message-ID: <20181123002549.GO6920@n2100.armlinux.org.uk> References: <20181119104040.12885-1-peter.ujfalusi@ti.com> <20181119184649.GE16897@darkstar.musicnaut.iki.fi> <6af8c6e7-bf5c-5555-161b-5d3fb7ecae43@ti.com> <20181120210406.GB24888@darkstar.musicnaut.iki.fi> <20181122102948.GN6920@n2100.armlinux.org.uk> <20181122151236.GA9611@n2100.armlinux.org.uk> <20181122222426.GC11423@darkstar.musicnaut.iki.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181122222426.GC11423@darkstar.musicnaut.iki.fi> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 23, 2018 at 12:24:26AM +0200, Aaro Koskinen wrote: > Hi, > > On Thu, Nov 22, 2018 at 03:12:36PM +0000, Russell King - ARM Linux wrote: > > On Thu, Nov 22, 2018 at 10:29:48AM +0000, Russell King - ARM Linux wrote: > > > On Tue, Nov 20, 2018 at 11:04:06PM +0200, Aaro Koskinen wrote: > > > > I had switched to PIO mode in 2015 since the WARNs about legacy DMA > > > > API were too annoying and flooding the console. And now that I tried > > > > using DMA again with g_ether, it doesn't work anymore. The device get's > > > > recognized on host side, but no traffic goes through. Switching back to > > > > PIO makes it to work again. > > > > > > A solution to that would be to do what the warning message says, and > > > update the driver to the DMAengine API. > > Fully agreed, but I was busy debugging other more serious issues, and > just wanted to get a reliable ssh or USB serial access to the device > without any extra noise, so switching to PIO using a module parameter > is probably what most users do in such situations. > > > Here's a partial conversion (not even build tested) - it only supports > > OUT transfers with dmaengine at the moment. > > Thanks, I'll take a closer look and try to do some testing hopefully > during the weekend. The patch was more for Peter to take a peek at - there's definitely some bits missing in the dmaengine driver (like the write to the LCH_CTRL register) that would need to be fixed somehow. However, it's worth noting that there is exactly one user of omap_set_dma_channel_mode(), which is omap-udc, which means any DMA channel made use of by omap-udc will have the LCH_CTRL register modified to LCH_P, and it will remain that way even if someone else subsequently makes use of the same channel. That's rather suspicious to me... maybe we can just initialise all LCH_CTRL registers to LCH_P in the dmaengine driver in that case! If not, then there's a bug right there. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up