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 3E802C6FD1D for ; Mon, 27 Mar 2023 15:11:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232666AbjC0PL2 (ORCPT ); Mon, 27 Mar 2023 11:11:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232523AbjC0PL1 (ORCPT ); Mon, 27 Mar 2023 11:11:27 -0400 Received: from mail-lf1-x132.google.com (mail-lf1-x132.google.com [IPv6:2a00:1450:4864:20::132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED9E33C1B for ; Mon, 27 Mar 2023 08:11:16 -0700 (PDT) Received: by mail-lf1-x132.google.com with SMTP id g17so11903186lfv.4 for ; Mon, 27 Mar 2023 08:11:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679929875; 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=M/m2d2cpr0u0mENErOZs6fKG3ZMIMx4Lh0v4RM7/bmM=; b=ZugIrca1ySnU3VFI4e6jpNQjnVMvyDRCO989hZiDcT68tAMd9caRg0w5MAcR3vCTDC z4GKjFuTeqCbnYpNDzjv2P2P0orEg6D3DN+pjT5BCMBGj7SE3gvxFa8e9nTurDVxSW1y hV5li0S+jrEXSzNnkFJ1mtZpbbrHJzpaDjdyFXlnSBCQhHk0sHgh35hGb/pMjwV+LGs+ dh+VfzNH2pIzlXIS8r9+KSZPr0umJznCQdYC43v+V2j0Mz7nincsFuYC8bvafHMvomIx gwRhEtbJHYPqFfaNYMiaHq7fI2GVRMUiOk7CyVXkdCUKXfTABXE8KtvxNStdbhZVQUJb FikQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679929875; 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=M/m2d2cpr0u0mENErOZs6fKG3ZMIMx4Lh0v4RM7/bmM=; b=llu69ID8UJQHokEfRPblszqykhk2RuvDeql0oeWsR+KCwbLy80CjLcGtCu4entVEDI E5S14SbIIfHctUwckfed/98LygoTkPLoMa5ros1vbA5PXwe7ftTD6xpkMyVqtpR4436I /5312ndJCIt24uIe+JNDwpB356wfrzRs2ehGNTVjOgTYrjYbNm4jVbmgGNJ1H7rv4CHm F6XQshmjdh7TO+6Adss9gOEcaRWp67mhU7+llPnQjq0ENEyd2xfHSw0lFnGms0kDod7j fhsH3UmtgMcXdREo27s2UxXHIgTsuNZiAwVOa66j3IzzwR+SxKPOo03Nop5fmRFHn1XX qETw== X-Gm-Message-State: AAQBX9cAq+z8gsbV7RH5j0CtbOp1K5PJZd3zAHXtncPiOaKqWOzg6BRl Z1dImVgs8ttHb3vob9y7gDQ= X-Google-Smtp-Source: AKy350Z+oNTAEN1qA2lvwoUrGWwjtShCQ04QsVgluSEB33qfzytXmu9qLbPJfBo0qR2pfSBY/ufybQ== X-Received: by 2002:ac2:555a:0:b0:4e8:45d5:53bf with SMTP id l26-20020ac2555a000000b004e845d553bfmr3280533lfk.40.1679929875106; Mon, 27 Mar 2023 08:11:15 -0700 (PDT) Received: from osv.localdomain ([89.175.180.246]) by smtp.gmail.com with ESMTPSA id u4-20020ac248a4000000b004cb8de497ffsm4652546lfg.154.2023.03.27.08.11.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Mar 2023 08:11:13 -0700 (PDT) From: Sergey Organov To: Stefan Wahren Cc: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , 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: Mon, 27 Mar 2023 18:11:12 +0300 In-Reply-To: (Stefan Wahren's message of "Mon, 27 Mar 2023 16:42:23 +0200") Message-ID: <87mt3ynsa7.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 Stefan Wahren writes: > Hi, > > Am 25.03.23 um 16:11 schrieb Uwe Kleine-König: [...] > today i had time to do some testing. At first i tested with different RXTL_DEFAULT values. > > 1 No overrun > 2 No overrun > 4 No overrun > 8 Overruns > > After that i look at the # echo 0 > /proc/sys/kernel/printk approach, > but this didn't change anything. The kernel is usually silent about > log message after boot and the console works still with echo. > Enforcing some driver to call printk periodically would make the > console unusuable. As you figured that printk() is not the cause, it must be something else that causes overruns, so there is no need to check printk case further. > > Finally i tried to disabled the spin_lock in imx_uart_console_write: > > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c > index f07c4f9ff13c..c342559ff1a2 100644 > --- a/drivers/tty/serial/imx.c > +++ b/drivers/tty/serial/imx.c > @@ -2007,14 +2007,12 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) > struct imx_port_ucrs old_ucr; > unsigned long flags; > unsigned int ucr1; > - int locked = 1; > + int locked = 0; > > if (sport->port.sysrq) > locked = 0; > else if (oops_in_progress) > locked = spin_trylock_irqsave(&sport->port.lock, flags); > - else > - spin_lock_irqsave(&sport->port.lock, flags); > > /* > * First, save UCR1/2/3 and then disable interrupts > > But the overruns still occured. Is this because the serial core > already helds a lock? This probably isn't even called when there is no printk() output, as user-space writes to /dev/console are rather performed through regular generic code, AFAIK. 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 5D1FBC6FD1D for ; Mon, 27 Mar 2023 15:12:23 +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=UJ+t6+Xq2tfmEr2aieZlQgrVdVSQzIY1H8529Ei4xoI=; b=V8ywSit2G8Ijrr 6DhBOj+ZeXcy32+bHrE+NYyGhl5ncbKuYlr00N1ZdetOqRotANcBmgiTEgIYLkDjJTCBWFJCudWn2 6F8SbZkUUYkElkaU6PNfyndHRkh0qjWjQ8oIL2cW41FWAGdzi2k6O9jF76jKdtzz7YOBRuEt8cXQz uOr/gJioBfOj7T5L00XBxJa9WV8LMZEvoTyIft+AUnQ0hov9MWC1RhVZAHQfA7WE03NFUwxeK+3jE uhucuU9dDJ+YSDzA6glxpPRE5QstJJpf1i9+/HcgOYlIT6umD2TIHbL18ySTOABD7MfDI/49rHluD jJJYgHdjSd5eIF/xERdg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pgoVP-00BTCE-1e; Mon, 27 Mar 2023 15:11:31 +0000 Received: from mail-lf1-x136.google.com ([2a00:1450:4864:20::136]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pgoVD-00BT7P-1D for linux-arm-kernel@lists.infradead.org; Mon, 27 Mar 2023 15:11:20 +0000 Received: by mail-lf1-x136.google.com with SMTP id i13so11886332lfe.9 for ; Mon, 27 Mar 2023 08:11:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679929875; 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=M/m2d2cpr0u0mENErOZs6fKG3ZMIMx4Lh0v4RM7/bmM=; b=ZugIrca1ySnU3VFI4e6jpNQjnVMvyDRCO989hZiDcT68tAMd9caRg0w5MAcR3vCTDC z4GKjFuTeqCbnYpNDzjv2P2P0orEg6D3DN+pjT5BCMBGj7SE3gvxFa8e9nTurDVxSW1y hV5li0S+jrEXSzNnkFJ1mtZpbbrHJzpaDjdyFXlnSBCQhHk0sHgh35hGb/pMjwV+LGs+ dh+VfzNH2pIzlXIS8r9+KSZPr0umJznCQdYC43v+V2j0Mz7nincsFuYC8bvafHMvomIx gwRhEtbJHYPqFfaNYMiaHq7fI2GVRMUiOk7CyVXkdCUKXfTABXE8KtvxNStdbhZVQUJb FikQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679929875; 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=M/m2d2cpr0u0mENErOZs6fKG3ZMIMx4Lh0v4RM7/bmM=; b=6gbg97azmUeUqEYb3frFleT8FRt+Pq02cL995wvKZJKy7PLi1OfogDgLu/5vRorpTx uUkTyzPnSGHbzZm5Sd8I6uRraFzV4C2p7RucYKfvIBTYBotPUxgMK7gGE3otNt/YWLmG kXg64hJV4vvrf/glOloWF9c4HXBVyhyJpHO9Rz3zVnxPPSjz26M7hljPU6In+KmlEqsK b83dW2xBWSLa4kMRIcqYhTW4Qnd65jHfbcOOIUyiCDO56Y59RgNlc01MYi4CsDg37sXo 2kun6xM8ksag8f5TIz7EtDL5/MGyhMisf8PTRa9IVpcpF1D8FnPbSn3Tvn9vFEK1SMpO sgxw== X-Gm-Message-State: AAQBX9ehHJi2ocWPFviu/SmmflONveAznD1wQOy9EMuYCGGKEfhpt7Jd QfPFo7XM4hEy3nVYAsN/a8CD9Cdu/eg= X-Google-Smtp-Source: AKy350Z+oNTAEN1qA2lvwoUrGWwjtShCQ04QsVgluSEB33qfzytXmu9qLbPJfBo0qR2pfSBY/ufybQ== X-Received: by 2002:ac2:555a:0:b0:4e8:45d5:53bf with SMTP id l26-20020ac2555a000000b004e845d553bfmr3280533lfk.40.1679929875106; Mon, 27 Mar 2023 08:11:15 -0700 (PDT) Received: from osv.localdomain ([89.175.180.246]) by smtp.gmail.com with ESMTPSA id u4-20020ac248a4000000b004cb8de497ffsm4652546lfg.154.2023.03.27.08.11.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Mar 2023 08:11:13 -0700 (PDT) From: Sergey Organov To: Stefan Wahren Cc: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , 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: Mon, 27 Mar 2023 18:11:12 +0300 In-Reply-To: (Stefan Wahren's message of "Mon, 27 Mar 2023 16:42:23 +0200") Message-ID: <87mt3ynsa7.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-20230327_081119_414416_EC09B3EB X-CRM114-Status: GOOD ( 21.20 ) 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 U3RlZmFuIFdhaHJlbiA8c3RlZmFuLndhaHJlbkBpMnNlLmNvbT4gd3JpdGVzOgoKPiBIaSwKPgo+ IEFtIDI1LjAzLjIzIHVtIDE2OjExIHNjaHJpZWIgVXdlIEtsZWluZS1Lw7ZuaWc6CgpbLi4uXQoK PiB0b2RheSBpIGhhZCB0aW1lIHRvIGRvIHNvbWUgdGVzdGluZy4gQXQgZmlyc3QgaSB0ZXN0ZWQg d2l0aCBkaWZmZXJlbnQgUlhUTF9ERUZBVUxUIHZhbHVlcy4KPgo+IDEgTm8gb3ZlcnJ1bgo+IDIg Tm8gb3ZlcnJ1bgo+IDQgTm8gb3ZlcnJ1bgo+IDggT3ZlcnJ1bnMKPgo+IEFmdGVyIHRoYXQgaSBs b29rIGF0IHRoZSAjIGVjaG8gMCA+IC9wcm9jL3N5cy9rZXJuZWwvcHJpbnRrIGFwcHJvYWNoLAo+ IGJ1dCB0aGlzIGRpZG4ndCBjaGFuZ2UgYW55dGhpbmcuIFRoZSBrZXJuZWwgaXMgdXN1YWxseSBz aWxlbnQgYWJvdXQKPiBsb2cgbWVzc2FnZSBhZnRlciBib290IGFuZCB0aGUgY29uc29sZSB3b3Jr cyBzdGlsbCB3aXRoIGVjaG8uCj4gRW5mb3JjaW5nIHNvbWUgZHJpdmVyIHRvIGNhbGwgcHJpbnRr IHBlcmlvZGljYWxseSB3b3VsZCBtYWtlIHRoZQo+IGNvbnNvbGUgdW51c3VhYmxlLgoKQXMgeW91 IGZpZ3VyZWQgdGhhdCBwcmludGsoKSBpcyBub3QgdGhlIGNhdXNlLCBpdCBtdXN0IGJlIHNvbWV0 aGluZyBlbHNlCnRoYXQgY2F1c2VzIG92ZXJydW5zLCBzbyB0aGVyZSBpcyBubyBuZWVkIHRvIGNo ZWNrIHByaW50ayBjYXNlIGZ1cnRoZXIuCgo+Cj4gRmluYWxseSBpIHRyaWVkIHRvIGRpc2FibGVk IHRoZSBzcGluX2xvY2sgaW4gaW14X3VhcnRfY29uc29sZV93cml0ZToKPgo+IGRpZmYgLS1naXQg YS9kcml2ZXJzL3R0eS9zZXJpYWwvaW14LmMgYi9kcml2ZXJzL3R0eS9zZXJpYWwvaW14LmMKPiBp bmRleCBmMDdjNGY5ZmYxM2MuLmMzNDI1NTlmZjFhMiAxMDA2NDQKPiAtLS0gYS9kcml2ZXJzL3R0 eS9zZXJpYWwvaW14LmMKPiArKysgYi9kcml2ZXJzL3R0eS9zZXJpYWwvaW14LmMKPiBAQCAtMjAw NywxNCArMjAwNywxMiBAQCBpbXhfdWFydF9jb25zb2xlX3dyaXRlKHN0cnVjdCBjb25zb2xlICpj bywgY29uc3QgY2hhciAqcywgdW5zaWduZWQgaW50IGNvdW50KQo+ICAJc3RydWN0IGlteF9wb3J0 X3VjcnMgb2xkX3VjcjsKPiAgCXVuc2lnbmVkIGxvbmcgZmxhZ3M7Cj4gIAl1bnNpZ25lZCBpbnQg dWNyMTsKPiAtCWludCBsb2NrZWQgPSAxOwo+ICsJaW50IGxvY2tlZCA9IDA7Cj4KPiAgCWlmIChz cG9ydC0+cG9ydC5zeXNycSkKPiAgCQlsb2NrZWQgPSAwOwo+ICAJZWxzZSBpZiAob29wc19pbl9w cm9ncmVzcykKPiAgCQlsb2NrZWQgPSBzcGluX3RyeWxvY2tfaXJxc2F2ZSgmc3BvcnQtPnBvcnQu bG9jaywgZmxhZ3MpOwo+IC0JZWxzZQo+IC0JCXNwaW5fbG9ja19pcnFzYXZlKCZzcG9ydC0+cG9y dC5sb2NrLCBmbGFncyk7Cj4KPiAgCS8qCj4gIAkgKglGaXJzdCwgc2F2ZSBVQ1IxLzIvMyBhbmQg dGhlbiBkaXNhYmxlIGludGVycnVwdHMKPgo+IEJ1dCB0aGUgb3ZlcnJ1bnMgc3RpbGwgb2NjdXJl ZC4gSXMgdGhpcyBiZWNhdXNlIHRoZSBzZXJpYWwgY29yZQo+IGFscmVhZHkgaGVsZHMgYSBsb2Nr PwoKVGhpcyBwcm9iYWJseSBpc24ndCBldmVuIGNhbGxlZCB3aGVuIHRoZXJlIGlzIG5vIHByaW50 aygpIG91dHB1dCwgYXMKdXNlci1zcGFjZSB3cml0ZXMgdG8gL2Rldi9jb25zb2xlIGFyZSByYXRo ZXIgcGVyZm9ybWVkIHRocm91Z2ggcmVndWxhcgpnZW5lcmljIGNvZGUsIEFGQUlLLgoKQmVzdCBy ZWdhcmRzLAotLSBTZXJnZXkgT3JnYW5vdgoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX18KbGludXgtYXJtLWtlcm5lbCBtYWlsaW5nIGxpc3QKbGludXgtYXJt LWtlcm5lbEBsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21h aWxtYW4vbGlzdGluZm8vbGludXgtYXJtLWtlcm5lbAo=