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 X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAC19C4338F for ; Tue, 27 Jul 2021 10:39:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B551F61882 for ; Tue, 27 Jul 2021 10:39:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236352AbhG0KjJ (ORCPT ); Tue, 27 Jul 2021 06:39:09 -0400 Received: from muru.com ([72.249.23.125]:55926 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236104AbhG0KjG (ORCPT ); Tue, 27 Jul 2021 06:39:06 -0400 Received: from localhost (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 3600D80F0; Tue, 27 Jul 2021 10:39:24 +0000 (UTC) Date: Tue, 27 Jul 2021 13:39:05 +0300 From: Tony Lindgren To: Andy Shevchenko Cc: Vignesh Raghavendra , "open list:SERIAL DRIVERS" , Jan Kiszka , Greg Kroah-Hartman , Jiri Slaby , Linux OMAP Mailing List , Linux ARM Mailing List , Linux Kernel Mailing List Subject: Re: [PATCH] serial: 8250: 8250_omap: Fix possible interrupt storm Message-ID: References: <20210511151955.28071-1-vigneshr@ti.com> <0ad948ac-f669-3d6d-5eca-4ca48d47d6a3@siemens.com> <56c5d73f-741c-2643-1c79-6dc13ebb05c7@ti.com> <0ae7e313-1ed7-f1be-e8a7-edd1286277a5@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org * Andy Shevchenko [210713 09:14]: > On Tue, Jul 13, 2021 at 11:54 AM Vignesh Raghavendra wrote: > > On 7/13/21 1:57 AM, andy@surfacebook.localdomain wrote: > > > Tue, Jun 22, 2021 at 11:53:38AM +0530, Vignesh Raghavendra kirjoitti: > > ... > > > > https://lore.kernel.org/linux-serial/20170206233000.3021-1-dianders@chromium.org/ > > > > I am not sure if reading UART_LSR is a good idea in the above patch. > > Some flags in LSR register are cleared on read (at least that's the case > > for UARTs on TI SoCs) and thus can result in loss of error/FIFO status > > information. > > > > > https://lore.kernel.org/linux-serial/1440015124-28393-1-git-send-email-california.l.sullivan@intel.com/ > > > > Looks like this never made it. > > Forgot to react to the above. Yes, they never made it because I > believe due to the exact reason you mentioned above. Also California > set up different experiments IIRC and it shows that the problem didn;t > fully disappear with his approach. But maybe yours will work better > (at least it's not the first time I have seen it on different hardware > according to people's contributions). Not sure if this is the same issue with noisy lines, but see also the following in case it's related: [PATCH 2/2] serial: 8250_omap: Handle optional overrun-throttle-ms property Also available at [0] below. Regards, Tony [0] https://lore.kernel.org/linux-omap/20210727103533.51547-1-tony@atomide.com/T/#m5f9da26c32503f2937d3d5977310ca337fa0cb5a