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 4E971C76196 for ; Fri, 24 Mar 2023 12:27:25 +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=tSgbr29E9KzmN84BarsEx/lv/O7LDuvOf94blGx0E1w=; b=1mSVrzqUg9pwBZ CgFZamR2t0ktzbXfS2+HGPrMPkuWV6r0UwB8uoFVxX4R5fzhXg05tumljdxVJ2LeSPY4HxG79K62P Eg0O4e0O2aoCScf6FJ07Rjzq6W9wVL47ZXKjuM2KsCRUrmANW6IV4AODRpDybz0d4vRQMg8yOfy8s UZJ/0WYf/UKIWNkOi74zTTR+qN2ZAruRQJcSLLF0uzNTdXfIY+BuEqlVs9Uee4kvt1XwbtRI2hqp7 c+edjxCmRY5iLiAUWSxMju+Kkz1cXIt6m+DufkNyOtUPQq4Xd6UllXxvIleap+FRh8N26mLaUeQxT lnG/bMVmOzLo0EUbPgYg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pfgV5-004Lrb-0H; Fri, 24 Mar 2023 12:26:31 +0000 Received: from mail11.truemail.it ([2001:4b7e:0:8::81]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pfgV1-004LqS-1W for linux-arm-kernel@lists.infradead.org; Fri, 24 Mar 2023 12:26:29 +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 21DF62065E; Fri, 24 Mar 2023 13:26:14 +0100 (CET) Date: Fri, 24 Mar 2023 13:26:09 +0100 From: Francesco Dolcini To: Ilpo =?iso-8859-1?Q?J=E4rvinen?= , Stefan Wahren Cc: Tomasz =?utf-8?Q?Mo=C5=84?= , Greg Kroah-Hartman , Jiri Slaby , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Sergey Organov , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , linux-serial@vger.kernel.org, Linux ARM , Shawn Guo , Stefan Wahren Subject: Re: Regression: serial: imx: overrun errors on debug UART Message-ID: References: <2c29454b-9369-4360-8eb4-c151f59460cb@i2se.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230324_052627_698008_228EF9A1 X-CRM114-Status: GOOD ( 14.29 ) 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="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello On Fri, Mar 24, 2023 at 01:47:59PM +0200, Ilpo J=E4rvinen wrote: > On Fri, 24 Mar 2023, Stefan Wahren wrote: > > after switching to Linux 6.1.21 on our Tarragon board (i.MX6ULL SoC), we > > experience the following issues with the debug UART (115200 baud, 8N1, = no > > hardware flow control): > > = > > - overrun errors if we paste in multiple text lines while system is idle > > - no reaction to single key strokes while system is on higher load > > = > > After reverting 7a637784d517 ("serial: imx: reduce RX interrupt frequen= cy") > > the issue disappear. > > = > > Maybe it's worth to mention that the Tarragon board uses two additional > > application UARTs with similiar baud rates (9600 - 115200 baud, no hard= ware > > flow control) for RS485 communication, but there are no overrun errors = (with > > and without the mention change). > = > This has come up earlier, see e.g.: > = > https://lore.kernel.org/linux-serial/20221003110850.GA28338@francesco-nb.= int.toradex.com/ yep, it looks exactly the same issue. We did not verify if this was affecting other UARTs. However, isn't RS485 = half-duplex? This is very likely a difference compared to the RS232 console port. I am also not really convinced this is a proper regression, while 7a637784d= 517 clearly is making the situation _worst_, we had some issues even before - unfortunately I have no much more details available. Francesco _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel