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_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 E531BC49ED7 for ; Mon, 16 Sep 2019 13:55:17 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B7F96214D9 for ; Mon, 16 Sep 2019 13:55:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="j3AuxqU7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7F96214D9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=emlix.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=7xo1BST3bqcqK9H73IHhz5B3/y0/jCydtiTtnRVFG0E=; b=j3AuxqU7kf57/Y BnsYSsvvZPwcvpDVKqoSNo9x6z4fnYarHCP7KeBdh26GwwTNzp6GsfmHh6Ssk8A0Eycgx0n4cGMpn 6ldjIVMPLQwE8sVIN/qE/z7ppJQV7KXlsA7vYkH6J2xny46sWse8TxLJd3/w54arZnnwIJEEsbSJP fK+D87pqclRyDxcVlS1hjQtvfX2PMiHqtnAij7SVSMuCQlZKYhviNBRINdIUVRACAU9wrLzeeRlyQ j+tEdnEoSuRuNCwPe57OulyZRZSjEndgIkFu7307Wqz9OZ4IQqwr9UqbOQobY45Oup7LjxVMlMUIm n1AK43HyjSV6pbVylf0w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1i9rTD-0006gu-DG; Mon, 16 Sep 2019 13:55:11 +0000 Received: from mx1.emlix.com ([188.40.240.192]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1i9rT9-0006Dh-5U for linux-arm-kernel@lists.infradead.org; Mon, 16 Sep 2019 13:55:09 +0000 Received: from mailer.emlix.com (unknown [81.20.119.6]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.emlix.com (Postfix) with ESMTPS id E92B15FAD2; Mon, 16 Sep 2019 15:55:04 +0200 (CEST) Subject: Re: [PATCH 0/4] Fix UART DMA freezes for iMX6 To: Fabio Estevam , Robin Gong , Fugang Duan References: <20190911144943.21554-1-philipp.puschmann@emlix.com> From: Philipp Puschmann Openpgp: preference=signencrypt Message-ID: <2613a28d-d363-ee4e-679a-e7442e6fde48@emlix.com> Date: Mon, 16 Sep 2019 15:55:04 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Language: de-DE X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190916_065507_368498_32F19EE3 X-CRM114-Status: GOOD ( 18.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-serial@vger.kernel.org, Greg Kroah-Hartman , linux-kernel , Vinod , NXP Linux Team , Sascha Hauer , Jiri Slaby , dmaengine@vger.kernel.org, Dan Williams , Shawn Guo , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Fabio, Am 12.09.19 um 20:23 schrieb Fabio Estevam: > Hi Philipp, > > Thanks for submitting these fixes. > > On Wed, Sep 11, 2019 at 11:50 AM Philipp Puschmann > wrote: >> >> For some years and since many kernel versions there are reports that >> RX UART DMA channel stops working at one point. So far the usual workaround was >> to disable RX DMA. This patches try to fix the underlying problem. >> >> When a running sdma script does not find any usable destination buffer to put >> its data into it just leads to stopping the channel being scheduled again. As >> solution we we manually retrigger the sdma script for this channel and by this >> dissolve the freeze. >> >> While this seems to work fine so far a further patch in this series increases >> the number of RX DMA periods for UART to reduce use cases running into such >> a situation. >> >> This patch series was tested with the current kernel and backported to >> kernel 4.15 with a special use case using a WL1837MOD via UART and provoking >> the hanging of UART RX DMA within seconds after starting a test application. >> It resulted in well known >> "Bluetooth: hci0: command 0x0408 tx timeout" >> errors and complete stop of UART data reception. Our Bluetooth traffic consists >> of many independent small packets, mostly only a few bytes, causing high usage >> of periods. >> >> >> Philipp Puschmann (4): >> dmaengine: imx-sdma: fix buffer ownership >> dmaengine: imx-sdma: fix dma freezes >> serial: imx: adapt rx buffer and dma periods >> dmaengine: imx-sdma: drop redundant variable > > I have some suggestions: > > 1. Please split this in two series: one for dmaengine and other one for serial > > 2. Please add Fixes tag when appropriate, so that the fixes can be > backported to stable kernels. > > 3. Please Cc Robin and Andy > > Thanks > Thanks for the hints. I will apply them if the contentual feedback is positive. p.s. Did you forget to add Andy? I don't see a Andy in the to- and cc-list. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel