From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA2BB1F619 for ; Tue, 2 Apr 2024 11:38:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712057937; cv=none; b=rQIYadvVhluSbqvMI3249BQiTbZcwnPHW6KKXOt6FWTQMVJNffGu/a9sLQ60BpLO1UmbLz78H1Mfl6/57Gul8EQziYY66aSm0F4HJZJxfyQhDldEXd5qMwQBqX0N06owvFsQdkB5fvOLGE8xpDJb/srm2mLP0szOJ1Ul3HNyBcA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712057937; c=relaxed/simple; bh=vC3XgrPyprneuVAKwm2B87wMA3ERHZHeO7QwzGK1YY0=; h=From:Date:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=nqmkgRc8uak/RrIpEhOCmhbmAp3ROGSHyzlOe9ntOP9VwqFtzdH2GRvhQZDgJ79SXQ8xTCH0g5nRA29thzfn7hEcOsxPYZ44SY3dzT3fkAab1osCV877seMdJ/U5Clxv6HNuqH0tjGNFAhCum2DOBJpAKPl6S2V6X81hV8ix8Iw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Hrz0FvWc; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Hrz0FvWc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712057936; x=1743593936; h=from:date:to:cc:subject:in-reply-to:message-id: references:mime-version:content-id; bh=vC3XgrPyprneuVAKwm2B87wMA3ERHZHeO7QwzGK1YY0=; b=Hrz0FvWcWtPHY686cXUGWxvndor2aADKRAlgCAalFn+WWsGQXsEclszj rwMc33fVbsw9xOWWVHC+vMGQLkmEoogMaDsoBmJhPNrqcRqs7tjzP0SSU hicdoKX1QiWaWCXQpFnd/xkwrXdeX/N5c0/eA9ZKX4ij7+cjgmZBKceZc wkhLInesZD5A6O8rJyRbqIbLtI771TuQGl0P73k0QKIjB4+M/TBLKu0Nl QNFh/CnoYKzojvm/Y8weAK0b6jQBiO0N7NdNd82YRmV2OXrHN5g/XRqoD LGjKc8ZGJkKYNKwx9BAhi/eLv5iU/Tfv52GZfOoVoXlk2GbLjB5rqtKHq g==; X-CSE-ConnectionGUID: 38cltsUKRyGYtcExi52xbg== X-CSE-MsgGUID: r1MMrNa1TuSNXFvnAYQXrg== X-IronPort-AV: E=McAfee;i="6600,9927,11031"; a="10184698" X-IronPort-AV: E=Sophos;i="6.07,174,1708416000"; d="scan'208";a="10184698" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Apr 2024 04:38:54 -0700 X-CSE-ConnectionGUID: x/VeaTrMQR+D2WNOW6jGVA== X-CSE-MsgGUID: BYgA3Tq8TnW/6mT9Exww5Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,174,1708416000"; d="scan'208";a="22726552" Received: from ijarvine-desk1.ger.corp.intel.com (HELO localhost) ([10.245.247.23]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Apr 2024 04:38:52 -0700 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Tue, 2 Apr 2024 14:38:48 +0300 (EEST) To: Feng Chunguo cc: Greg KH , "fengchunguo@126.com" , Andy Shevchenko , Jiri Slaby , LKML Subject: Re: [PATCH] tty: serial: fixed uart irq maybe cause irq storm In-Reply-To: <727f9378143988cc621a116574fe5252a8f42301.f0b607c1.a18c.4c73.a561.fef5700437ab@feishu.cn> Message-ID: <7dd8f053-aaba-beaa-0f2f-118b0b1c2d85@linux.intel.com> References: <1711963801-184362-1-git-send-email-fengchunguo@126.com> <2024040147-stinging-payback-04f5@gregkh> <727f9378143988cc621a116574fe5252a8f42301.f0b607c1.a18c.4c73.a561.fef5700437ab@feishu.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="8323328-1196340581-1712057626=:1019" Content-ID: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-1196340581-1712057626=:1019 Content-Type: text/plain; CHARSET=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Content-ID: On Mon, 1 Apr 2024, Feng Chunguo wrote: > Hi Greg KH=EF=BC=8C >=20 > Sent this path again. >=20 > =C2=A0the irq should not be turned off here, what happens if some data co= mes in while this > function is running?=C2=A0 Will it be lost? > --> lost=EF=BC=8Cnot receive other irq. >=20 > =C2=A0When the uart was switching the baud rate from one to other,=C2=A0 = this issue can be > reproduced. >> This feels wrong, >> the irq should not be turned off here, what happens if some data comes i= n while this >> function is running? Will it be lost? thanks, greg k-h Changing rate always risks losing what's currently on wire due to timing=20 related corruption, I don't think there there's a way around that IRQ=20 being enabled or not. --=20 i. --8323328-1196340581-1712057626=:1019--