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 71832C433EF for ; Thu, 7 Jul 2022 20:45:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235948AbiGGUpU (ORCPT ); Thu, 7 Jul 2022 16:45:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231875AbiGGUpT (ORCPT ); Thu, 7 Jul 2022 16:45:19 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFC082409B; Thu, 7 Jul 2022 13:45:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657226718; x=1688762718; h=message-id:subject:from:reply-to:to:cc:date:in-reply-to: references:mime-version:content-transfer-encoding; bh=pEzztt4x7TuSYLGDhfj8WnqW4H1+jbfMqaaC+PMJx+U=; b=JBcsR1FVYwEVkgTc00aKuStw9AVTE9EhBFbSmo0TgeiMMbSWmoTxc11G 5OMSBY+vCEGHXQ6aG/tNAlz2TMGhGjlHpmkkj7ft6+7RSKH30NyJHYR4H 4YltrKwM6J0E/IBUp3hmvFS/3x/IUCQmSmlnR+YZW+iQ6KICEAblP7yhM 24jzAqY0ffTZj2hvofq1H9cY57iKSfaFPj7ZDyXKm3RymNXoZj/Pwjd5M O820jhs3cSdiZl6yu0rz23M+sXTdc5+BRH79fsOh31aUdXGzoBW10n9sD GOclE5cEfqCi+bxbLsZJ3X/CqmeewP814t7TEJflSrQp1wBc6DDgJWWez A==; X-IronPort-AV: E=McAfee;i="6400,9594,10401"; a="284859965" X-IronPort-AV: E=Sophos;i="5.92,253,1650956400"; d="scan'208";a="284859965" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jul 2022 13:45:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,253,1650956400"; d="scan'208";a="651284219" Received: from wopr.jf.intel.com ([10.54.75.125]) by fmsmga008.fm.intel.com with ESMTP; 07 Jul 2022 13:45:17 -0700 Message-ID: <51b9e2cc3baf61a604bd239b736ec2d12f1f6695.camel@linux.intel.com> Subject: Re: PNP0501 serial driver takes almost 2 seconds to suspend/resume (printk issue) From: Todd Brandt Reply-To: todd.e.brandt@linux.intel.com To: john.ogness@linutronix.de, pmladek@suse.com Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, senozhatsky@chromium.org, rostedt@goodmis.org Date: Thu, 07 Jul 2022 13:45:17 -0700 In-Reply-To: <12fb98fe27e23e3f74a139e5e8eb83a97a343372.camel@linux.intel.com> References: <12fb98fe27e23e3f74a139e5e8eb83a97a343372.camel@linux.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Adding printk maintainers to the thread On Thu, 2022-07-07 at 13:31 -0700, Todd Brandt wrote: > Ever since 5.19.0-rc1 the serial device has taken almost a second > longer in both suspend and resume. This effect is witnessed in half > the > machines in our lab (~10 machines). It occurs on dell, asus, gigabyte > and other machines so it's not hardware specific. > > I opened a bugzilla issue which includes the git bisect: > https://bugzilla.kernel.org/show_bug.cgi?id=216216 > > > Bad commit: > > commit 3b604ca81202eea2a917eb6491e90f610fba0ec7 > Author: John Ogness > Date: Thu Apr 21 23:28:46 2022 +0206 > > printk: add pr_flush() > > Provide a might-sleep function to allow waiting for console > printers > to catch up to the latest logged message. > > Use pr_flush() whenever it is desirable to get buffered messages > printed before continuing: suspend_console(), resume_console(), > console_stop(), console_start(), console_unblank(). > > Signed-off-by: John Ogness > Reviewed-by: Petr Mladek > Signed-off-by: Petr Mladek > Link: > https://lore.kernel.org/r/20220421212250.565456-12-john.ogness@linutronix.de > > include/linux/printk.h | 7 +++++ > kernel/printk/printk.c | 83 > ++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 90 insertions(+)