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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18D01C6FD1F for ; Sat, 25 Mar 2023 18:30:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230354AbjCYSac (ORCPT ); Sat, 25 Mar 2023 14:30:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229446AbjCYSac (ORCPT ); Sat, 25 Mar 2023 14:30:32 -0400 Received: from mail-lj1-x22c.google.com (mail-lj1-x22c.google.com [IPv6:2a00:1450:4864:20::22c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EAAE5C170 for ; Sat, 25 Mar 2023 11:30:30 -0700 (PDT) Received: by mail-lj1-x22c.google.com with SMTP id h9so4968833ljq.2 for ; Sat, 25 Mar 2023 11:30:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679769029; h=content-transfer-encoding:mime-version:user-agent:message-id :in-reply-to:date:references:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to; bh=ZAGnDYDwy+EfPH5YuYCiFqndH71GSU/qDTqOWjnek4k=; b=c/mxEMDRuUq3lT1zQtjt+CIfDNQ2IsHjMrrtxCdhC9S/xFlC9PMQbh+Yjo0tL7NWyV Fev3/zVRVhq6PXHR2lbIqTRnTdRAZB3eSvHEAzztktcxiYsCz+THFI+PPkx2eNf6dX5D J9L45HHafq/wJecTOvGcFqCAaZdp1ycYpJZLc19j6OCgdh/xIvVQRDblt7VNxoIH6Fzl l0MtzYM+7Wle6TqaaKLYYmPnydx5el1o/mg8GcOjCSPOpLxmHQlfKIXflBetg77H2N/Z LpIBLzNTQsXss+eCaUyI+9e8dEpHZyJfFjd+quojCDcR3MsRfdrFeHIlrs0mnKqDX2b9 wgqw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679769029; h=content-transfer-encoding:mime-version:user-agent:message-id :in-reply-to:date:references:subject:cc:to:from:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=ZAGnDYDwy+EfPH5YuYCiFqndH71GSU/qDTqOWjnek4k=; b=LhA3gRxFNkDeGXtJ0o2St9PNxyYuf0JL4fm+4kMbBy1jUCvyIvIVpw161nBkal7aHG E2PZVU7+RLIrZoHY7G9B01Bbe/mN0OqCqFbDXKNuZphSXXHxFwYSe1FHNG2r9fkOYZI+ bqVDiZhHO1rYINNguBx8PGk3ZgVy54fAeYVY+f4rmPVZN+TwVIsWxpWoxp6k6FyiWe2Q UXiInV9Thh1UJGPHYuSeQZseZ1Vd5qGE5n1xb1yX4vLx8uErGDEiDOYUArWcWIgWemIR 2vpSBJCM+MaIsDoR3ll+f1bKVL0EGPfLJ3DtpUyxI3hcdmDuO+34nIK3Z6v8j/2AZsvl s3lg== X-Gm-Message-State: AAQBX9cY6fDNF+YEiODhlM1h3b7veuMcC5YLTRhGRPYJ+oGKlYhByOr0 kd9ZulznQDZxCvvDTrf4LEk= X-Google-Smtp-Source: AKy350aLiZCE0feZw6DlWKMzCLfF21TKvmKzdFp7chc6KDbprDjDxzfHhD51bHhHEatAkRX7vdZFqw== X-Received: by 2002:a2e:6808:0:b0:29a:f63d:d7bf with SMTP id c8-20020a2e6808000000b0029af63dd7bfmr2090330lja.22.1679769029079; Sat, 25 Mar 2023 11:30:29 -0700 (PDT) Received: from osv.localdomain ([89.175.180.246]) by smtp.gmail.com with ESMTPSA id g21-20020a2e9e55000000b0029f3e2efbb9sm2004490ljk.90.2023.03.25.11.30.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 25 Mar 2023 11:30:28 -0700 (PDT) From: Sergey Organov To: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= Cc: Stefan Wahren , Fabio Estevam , Ilpo =?utf-8?Q?J=C3=A4rvinen?= , 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 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> Date: Sat, 25 Mar 2023 21:30:26 +0300 In-Reply-To: <20230325151100.mskydt3hwbnspqp4@pengutronix.de> ("Uwe =?utf-8?Q?Kleine-K=C3=B6nig=22's?= message of "Sat, 25 Mar 2023 16:11:00 +0100") Message-ID: <87edpc65vh.fsf@osv.gnss.ru> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Hello, Uwe Kleine-König writes: > Hello, > > On Sat, Mar 25, 2023 at 12:31:01PM +0100, Stefan Wahren wrote: [...] > > So the current theory that the issue occurs because of a combination of: > > - With a higher watermark value the irq triggers later and so there is > less time the until the ISR must run before an overflow happens; and > > - serial console activity disables irqs for a (relative) long time > > right? > > So on an UP system the problem should occur also on a non-console > port? That's exactly what I've experienced, especially when console baud rate was lower than that of other port(s). I had console at 115200, and got immediate problems on another port working at 460800 whenever relatively lengthy printk output has been emitted (in my case it was info from wlan driver.) > Local irqs are only disabled if some printk is about to be emitted, > isn't it? Yep, and this allows for easy check if it's indeed printk that causes this by eliminating the output using # echo 0 > /proc/sys/kernel/printk > Does this match the error you're seeing? > > That makes me wonder if the error doesn't relate to the UART being a > console port, but the UART being used without DMA?! (So the patch above > fixes the problem for you because on the console port no DMA is used?) Indeed DMA is likely to be able to hide the problem if the cause is printk, though all my results were obtained on DMA-disabled ports, and I never checked with DMA enabled, so unfortunately I have no tested confirmation of this idea. Best regards, -- Sergey Organov 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 E635BC6FD1C for ; Sat, 25 Mar 2023 18:31:53 +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:MIME-Version:Message-ID:In-Reply-To: Date:References:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pBZfLRSTVqVf9/NqoWVdUSCjxBQysfcCbsHDkBhRla0=; b=Ci3ueZyMaPqr53 JANh7OKxn+WmqNA5CjAFCyvT2syZssRVe7RDCITI0derVCB6cfWo/I42QsL5U3umXQ83/gcgyDzfP xGfIL+wcP2ojsMKprPyBnfGRKj0ZhaOKFd68cG9vg8MQJ/xYxz5ZMdYUEqRvLYLeYe+0yaeNzFuLj tav3j0yES56Nnr3u4UET1Xgxf49nnYp6golxCbPwFH9ORpsb8oh6CT7m5KOxz2GuOFzuR8mGwTeX3 UfPSErRbcVYcT68MRH8MYuieMgvrFTp6yz5F8VXqs/wcAFS2vzdnfpgHbrriFFaNKw0XoILA1RVq7 EQlwqxo3gi5o0Eev6bIg==; 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Sat, 25 Mar 2023 11:30:28 -0700 (PDT) From: Sergey Organov To: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= Cc: Stefan Wahren , Fabio Estevam , Ilpo =?utf-8?Q?J=C3=A4rvinen?= , 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 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> Date: Sat, 25 Mar 2023 21:30:26 +0300 In-Reply-To: <20230325151100.mskydt3hwbnspqp4@pengutronix.de> ("Uwe =?utf-8?Q?Kleine-K=C3=B6nig=22's?= message of "Sat, 25 Mar 2023 16:11:00 +0100") Message-ID: <87edpc65vh.fsf@osv.gnss.ru> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230325_113032_251932_E997378E X-CRM114-Status: GOOD ( 22.37 ) 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="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org SGVsbG8sCgpVd2UgS2xlaW5lLUvDtm5pZyA8dS5rbGVpbmUta29lbmlnQHBlbmd1dHJvbml4LmRl PiB3cml0ZXM6Cj4gSGVsbG8sCj4KPiBPbiBTYXQsIE1hciAyNSwgMjAyMyBhdCAxMjozMTowMVBN ICswMTAwLCBTdGVmYW4gV2FocmVuIHdyb3RlOgpbLi4uXQo+Cj4gU28gdGhlIGN1cnJlbnQgdGhl b3J5IHRoYXQgdGhlIGlzc3VlIG9jY3VycyBiZWNhdXNlIG9mIGEgY29tYmluYXRpb24gb2Y6Cj4K PiAgLSBXaXRoIGEgaGlnaGVyIHdhdGVybWFyayB2YWx1ZSB0aGUgaXJxIHRyaWdnZXJzIGxhdGVy IGFuZCBzbyB0aGVyZSBpcwo+ICAgIGxlc3MgdGltZSB0aGUgdW50aWwgdGhlIElTUiBtdXN0IHJ1 biBiZWZvcmUgYW4gb3ZlcmZsb3cgaGFwcGVuczsgYW5kCj4KPiAgLSBzZXJpYWwgY29uc29sZSBh Y3Rpdml0eSBkaXNhYmxlcyBpcnFzIGZvciBhIChyZWxhdGl2ZSkgbG9uZyB0aW1lCj4KPiByaWdo dD8KPgo+IFNvIG9uIGFuIFVQIHN5c3RlbSB0aGUgcHJvYmxlbSBzaG91bGQgb2NjdXIgYWxzbyBv biBhIG5vbi1jb25zb2xlCj4gcG9ydD8KClRoYXQncyBleGFjdGx5IHdoYXQgSSd2ZSBleHBlcmll bmNlZCwgZXNwZWNpYWxseSB3aGVuIGNvbnNvbGUgYmF1ZApyYXRlIHdhcyBsb3dlciB0aGFuIHRo YXQgb2Ygb3RoZXIgcG9ydChzKS4gSSBoYWQgY29uc29sZSBhdCAxMTUyMDAsCmFuZCBnb3QgaW1t ZWRpYXRlIHByb2JsZW1zIG9uIGFub3RoZXIgcG9ydCB3b3JraW5nIGF0IDQ2MDgwMCB3aGVuZXZl cgpyZWxhdGl2ZWx5IGxlbmd0aHkgcHJpbnRrIG91dHB1dCBoYXMgYmVlbiBlbWl0dGVkIChpbiBt eSBjYXNlIGl0IHdhcwppbmZvIGZyb20gd2xhbiBkcml2ZXIuKQoKPiBMb2NhbCBpcnFzIGFyZSBv bmx5IGRpc2FibGVkIGlmIHNvbWUgcHJpbnRrIGlzIGFib3V0IHRvIGJlIGVtaXR0ZWQsCj4gaXNu J3QgaXQ/CgpZZXAsIGFuZCB0aGlzIGFsbG93cyBmb3IgZWFzeSBjaGVjayBpZiBpdCdzIGluZGVl ZCBwcmludGsgdGhhdCBjYXVzZXMKdGhpcyBieSBlbGltaW5hdGluZyB0aGUgb3V0cHV0IHVzaW5n CgojIGVjaG8gMCA+IC9wcm9jL3N5cy9rZXJuZWwvcHJpbnRrCgo+IERvZXMgdGhpcyBtYXRjaCB0 aGUgZXJyb3IgeW91J3JlIHNlZWluZz8KPgo+IFRoYXQgbWFrZXMgbWUgd29uZGVyIGlmIHRoZSBl cnJvciBkb2Vzbid0IHJlbGF0ZSB0byB0aGUgVUFSVCBiZWluZyBhCj4gY29uc29sZSBwb3J0LCBi dXQgdGhlIFVBUlQgYmVpbmcgdXNlZCB3aXRob3V0IERNQT8hIChTbyB0aGUgcGF0Y2ggYWJvdmUK PiBmaXhlcyB0aGUgcHJvYmxlbSBmb3IgeW91IGJlY2F1c2Ugb24gdGhlIGNvbnNvbGUgcG9ydCBu byBETUEgaXMgdXNlZD8pCgpJbmRlZWQgRE1BIGlzIGxpa2VseSB0byBiZSBhYmxlIHRvIGhpZGUg dGhlIHByb2JsZW0gaWYgdGhlIGNhdXNlIGlzCnByaW50aywgdGhvdWdoIGFsbCBteSByZXN1bHRz IHdlcmUgb2J0YWluZWQgb24gRE1BLWRpc2FibGVkIHBvcnRzLCBhbmQgSQpuZXZlciBjaGVja2Vk IHdpdGggRE1BIGVuYWJsZWQsIHNvIHVuZm9ydHVuYXRlbHkgSSBoYXZlIG5vIHRlc3RlZApjb25m aXJtYXRpb24gb2YgdGhpcyBpZGVhLgoKQmVzdCByZWdhcmRzLAotLSBTZXJnZXkgT3JnYW5vdgoK X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KbGludXgtYXJt LWtlcm5lbCBtYWlsaW5nIGxpc3QKbGludXgtYXJtLWtlcm5lbEBsaXN0cy5pbmZyYWRlYWQub3Jn Cmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtYXJtLWtl cm5lbAo=