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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 05A98C004E4 for ; Wed, 13 Jun 2018 16:08:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB3F5208B2 for ; Wed, 13 Jun 2018 16:08:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB3F5208B2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de 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 S934667AbeFMQIC (ORCPT ); Wed, 13 Jun 2018 12:08:02 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:51769 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934250AbeFMQIB (ORCPT ); Wed, 13 Jun 2018 12:08:01 -0400 Received: from weser.hi.pengutronix.de ([2001:67c:670:100:fa0f:41ff:fe58:4010]) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1fT8JP-00053o-V8; Wed, 13 Jun 2018 18:07:55 +0200 Message-ID: <1528906072.21021.22.camel@pengutronix.de> Subject: Re: [PATCH v3 0/6] add virt-dma support for imx-sdma From: Lucas Stach To: Robin Gong , "s.hauer@pengutronix.de" , "vkoul@kernel.org" , "dan.j.williams@intel.com" Cc: "dmaengine@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , dl-linux-imx Date: Wed, 13 Jun 2018 18:07:52 +0200 In-Reply-To: <1528822708.13468.9.camel@nxp.com> References: <1528729173-28684-1-git-send-email-yibin.gong@nxp.com> <1528714877.2842.3.camel@pengutronix.de> <1528822708.13468.9.camel@nxp.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:fa0f:41ff:fe58:4010 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Robin, Am Dienstag, den 12.06.2018, 08:58 +0000 schrieb Robin Gong: > Hi Lucas, > Is the below DEAD LOCK issue same as your side? If yes, then > I'm afraid that we have to make another patch for uart to split dma > functions in uart driver out of the code area which protected by > port.lock. The warning make sense since allocate sdma bd memory > dynamically in virt-dma instead of static allocated as before. I'll > make another uart patch into my next version patchset. Yes, I see the same lockdep splat on my system. Though I'm not sure if this is really the root cause of the issue I see. I'm getting timeouts for a serdev attached device and I don't think this system ever enters memory reclaim, so the issue reported by lockdep seems to be a mostly theoretical on this system. But lets see how far I get when you fixed this issue, maybe the real bug is hiding behind this one. Regards, Lucas