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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2988CC74A5B for ; Sun, 26 Mar 2023 18:22:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=J8iGWLyrfRFUl6Z8yzOV64bM+TyAVpcsi8oicR7Xp9w=; b=p+fatPVmidS84n Hx6HB0OD5/nMk+UV4K88UHfip8a36OvMDvp2FFpj9RhefVfejeZjIlt2lbcbpQiux5Jy1tQkjyrpS kvkS70edKgoe3poJcsJi5fbu6b3hQnyapAqjTZqDNV9BYs4Z7AxUFcgZieAbU8tqgM9/ZCCnbhG9j gZHUSUtJZpJwnjEk2nzYyV9eFB+ZSjItqOYGPbIuP+FsBo9RDt+PHFigqHnXKg9pxzzdjn3qzVDWb RFcHOzHk1yfSXJk2bB21gJVbs2N7LNgqoLsCEvvmwBEa8XqoD5xWvuzcbPtAj0knlSTcNpWqy06i1 ZLStnSnarLqhBzaD7XEg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pgUzu-008zEz-2G; Sun, 26 Mar 2023 18:21:42 +0000 Received: from mail11.truemail.it ([217.194.8.81]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pgUzr-008zCM-0e for linux-arm-kernel@lists.infradead.org; Sun, 26 Mar 2023 18:21:41 +0000 Received: from francesco-nb.int.toradex.com (93-49-2-63.ip317.fastwebnet.it [93.49.2.63]) by mail11.truemail.it (Postfix) with ESMTPA id 3970220618; Sun, 26 Mar 2023 20:21:28 +0200 (CEST) Date: Sun, 26 Mar 2023 20:21:24 +0200 From: Francesco Dolcini To: Sergey Organov Cc: Stefan Wahren , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Fabio Estevam , Ilpo =?iso-8859-1?Q?J=E4rvinen?= , Stefan Wahren , linux-serial@vger.kernel.org, Greg Kroah-Hartman , Sascha Hauer , NXP Linux Team , Pengutronix Kernel Team , Shawn Guo , Jiri Slaby , Tomasz =?utf-8?Q?Mo=C5=84?= , Linux ARM Subject: Re: Regression: serial: imx: overrun errors on debug UART Message-ID: References: <2c29454b-9369-4360-8eb4-c151f59460cb@i2se.com> <9e22f237-f3ee-0415-9e6b-89a137769b8f@i2se.com> <5d59dec6-9f6f-7b20-1221-f57c94b29cca@i2se.com> <20230325151100.mskydt3hwbnspqp4@pengutronix.de> <07d37e3e-dfe2-9e6e-a981-8d3c6a9fc5f5@i2se.com> <878rfk64hj.fsf@osv.gnss.ru> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <878rfk64hj.fsf@osv.gnss.ru> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230326_112139_406280_AE098F3B X-CRM114-Status: UNSURE ( 7.41 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Mar 25, 2023 at 10:00:24PM +0300, Sergey Organov wrote: > In correctly working RT system this doesn't typically happen, as CPUs > are way faster than typical UART speeds, and are able to handle the > loads easily, provided UART has decent FIFO. It's disabling IRQs for > prolonged times that makes shit happen. The first time we were looking into this issue was before 7a637784d517 and with a PREEMPT-RT patched kernel (if I remember correctly it was a v5.4). The system was not loaded at all and it was pretty surprising the behavior, because of the reasons you just wrote here. Francesco _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel