From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 82EA2231A3B; Sun, 30 Aug 2026 07:42:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788075771; cv=none; b=Cic9wpvlo2CfEfIxUC8jcdrFXzESZGMhj9mAlm6MKvisMuQMC/O8oLaXQWf0Fs0w8MwtS9ACfWx/LjE5Fkn/YFKuXPv5gSwXwLxNdJWajdn7btbFLG8l3K+0gwhQoGQ81j10yJVkyg0gWw4Kzlb1jYq8AOc8NBx0OFyGI4XJfp8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788075771; c=relaxed/simple; bh=1GxxShbqhyWR5JXZGet2lOpYv+Ym/BROEPbMOYsx7J8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Uh9M5jTOf0ZgJ1w7vNNPSkFWfhiTkKa51zUJSWXo8coGAj4aBTnNDRytCTsE2z1AlWjIUhGfesy80/AVj3WeVCYtx+NIhMdzfIFhoW5c1xn66j10YCcwBMdG5ntcZxKB/ZK+Ai5Y3wyH46Oa20qhGfwdn+9IaFi8osvdGD3neHA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=OOakZbd8; arc=none smtp.client-ip=198.175.65.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="OOakZbd8" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1788075769; x=1819611769; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=1GxxShbqhyWR5JXZGet2lOpYv+Ym/BROEPbMOYsx7J8=; b=OOakZbd8douTOF+V8YSzJPTuOxEFUQy13OW0QPUilZrdW5+3iNt1cKmd zZdI+yEy4L/5wnfSc1sQJ6Ba1IEqkpT6okzf03OJOtI6hNjN+kSSuKBVN erQk2iptCA27wi2DNP+/uw44QDgddnRImxsK/Dct0CZkgiaXnShXvuCGi hWhWC6UlnVjpQPnc6Q+t9+6YZoFcVYdyYP6kUxEh2gS5Dhdfpf21IHIxr aOlIbP1ZoIQs4XIwCv2uwoUSwBffRAOnmnTsJlgcnVUg68clOZFMyERCc lo/PJpNLr3Mn+1EMtDm7UC5JM+7euRgVCTU5zbmTczrVSgzwIMHnEVJrN w==; X-CSE-ConnectionGUID: L2xdrHIXSyuBPe1crp67jg== X-CSE-MsgGUID: /g7h99q9SpabKsQxoCpBcQ== X-IronPort-AV: E=McAfee;i="6800,10657,11890"; a="92381499" X-IronPort-AV: E=Sophos;i="6.25,251,1779174000"; d="scan'208";a="92381499" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2026 00:42:48 -0700 X-CSE-ConnectionGUID: NrKHh4eVRFCvL58bT4Fh/Q== X-CSE-MsgGUID: IlsWzdGqTimm488ePG15kA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,251,1779174000"; d="scan'208";a="264243276" Received: from abityuts-desk1.ger.corp.intel.com (HELO localhost) ([10.245.245.243]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2026 00:42:44 -0700 Date: Sun, 30 Aug 2026 10:42:42 +0300 From: Andy Shevchenko To: Jon Hunter Cc: Sebastian Andrzej Siewior , John Ogness , Greg Kroah-Hartman , Jiri Slaby , Andy Shevchenko , Petr Mladek , Thierry Reding , linux-kernel@vger.kernel.org, Ilpo =?iso-8859-1?Q?J=E4rvinen?= , Crescent Hsieh , Hugo Villeneuve , linux-serial@vger.kernel.org, "linux-tegra@vger.kernel.org" Subject: Re: [PATCH tty 1/1] serial: 8250: Change console_msr_work to IRQ_WORK_LAZY Message-ID: References: <20260828155811.270462-1-john.ogness@linutronix.de> <20260828155811.270462-2-john.ogness@linutronix.de> <20260828160652.TQBsi8oO@linutronix.de> <0c2c424f-0372-4626-b14e-7697d98e6b20@nvidia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0c2c424f-0372-4626-b14e-7697d98e6b20@nvidia.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Fri, Aug 28, 2026 at 06:06:50PM +0100, Jon Hunter wrote: > On 28/08/2026 17:06, Sebastian Andrzej Siewior wrote: > > On 2026-08-28 18:04:08 [+0206], John Ogness wrote: > > > For some platforms it is a problem to queue irq_work when entering > > > cpuidle states. Since irq_work is used for deferred MSR handling, > > > any atomic console printing when entering cpuidle states can lead > > > to the affected hardware hanging. Tegra20 and Tegra30 are examples > > > of such platforms. Avoiding raising the irq_work IRQ has shown to > > > circumvent the problem. > > > > I would argue that this is done for the benefit of less interrupts since > > there no need to handle console_msr_work immediately. With the side > > effect that it might fix a bug that was not yet reported on Tegra[23]0. > > > > Ideally the Tegra folks should figure out what exactly is broken instead > > of adding duct tape everywhere else. > > Yes that would be ideal. Unfortunately these are old devices now and very > much in maintenance mode so getting to the bottom of this now is unlikely. > You may say then why don't we completely deprecate these, but then you > could argue the other way and say they have been working fine up until > now. This is a trade-off between burden of supporting them vs. developing and move on on more important things. Personally I consider non-blocking console feature is *much* more important than a few "working fine up until now" outdated platforms (side example, recently the whole i486 support was ripped off, while working fine...). -- With Best Regards, Andy Shevchenko