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 3B90EC433F5 for ; Tue, 23 Nov 2021 09:26:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234946AbhKWJ3J (ORCPT ); Tue, 23 Nov 2021 04:29:09 -0500 Received: from mga12.intel.com ([192.55.52.136]:55499 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233911AbhKWJ3I (ORCPT ); Tue, 23 Nov 2021 04:29:08 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10176"; a="215016639" X-IronPort-AV: E=Sophos;i="5.87,257,1631602800"; d="scan'208";a="215016639" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2021 01:26:00 -0800 X-IronPort-AV: E=Sophos;i="5.87,257,1631602800"; d="scan'208";a="508929417" Received: from smile.fi.intel.com ([10.237.72.184]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2021 01:25:56 -0800 Received: from andy by smile.fi.intel.com with local (Exim 4.95) (envelope-from ) id 1mpS3f-009jMP-NQ; Tue, 23 Nov 2021 11:25:47 +0200 Date: Tue, 23 Nov 2021 11:25:47 +0200 From: Andy Shevchenko To: Jay Dolan Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Jiri Slaby Subject: Re: [PATCH v1 0/2] serial: 8250_pci: Split Pericom driver Message-ID: References: <20211117145750.43911-1-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 22, 2021 at 09:19:09PM -0800, Jay Dolan wrote: > On 11/22/21 4:48 AM, Andy Shevchenko wrote: > > On Mon, Nov 22, 2021 at 02:47:20PM +0200, Andy Shevchenko wrote: > > > On Thu, Nov 18, 2021 at 10:32:51PM -0800, Jay Dolan wrote: > > > > On 11/17/21 6:57 AM, Andy Shevchenko wrote: > > > > > Split Pericom driver to a separate module. > > > > > While at it, re-enable high baud rates. > > > > > > > > > > Jay, can you, please, test this on as many hardware as you have? > > > > > > ... > > > > > > > * Add in pericom_do_startup() because the UPF_MAGIC_MULTIPLIER doesn't > > > > stick. > > > > > > Can't find an evidence that this is the case. Can you recheck this (reading > > > flags back via sysfs or so)? So, for v2 I'll leave my approach. > > > > Otherwise how the other drivers which are using that flag survive? If it's > > indeed an issue, it should be fixed on generic level. > > > > I modified pericom_do_startup to log when the UPF_MAGIC_MULTIPLIER flag was > present. Then tried to set the port to 3000000 a few times. The port > stayed at 9600. It looks like pericom_do_startup() is getting called twice > per port on boot, and the flag is gone with the second one. > > [ 4.925577] [J4D] flag present > [ 4.926121] [J4D[ flag not present > [ 4.926843] [J4D] flag present > [ 4.927415] [J4D[ flag not present > [ 4.928106] [J4D] flag present > [ 4.928673] [J4D[ flag not present > [ 4.929419] [J4D] flag present > [ 4.930447] [J4D[ flag not present > > [ 49.528504] [J4D[ flag not present > [ 51.675240] [J4D[ flag not present > [ 59.617954] [J4D[ flag not present > > Then I modified it to log when it was adding the flag in. The port was set > to 3000000. Also the flag only needed to be added in once. It sticks after > the first time. > > [ 4.647546] [J4D] flag present > [ 4.648119] [J4D] flag not present(adding) > [ 4.648778] [J4D] flag present > [ 4.649330] [J4D] flag not present(adding) > [ 4.650001] [J4D] flag present > [ 4.650537] [J4D] flag not present(adding) > [ 4.651192] [J4D] flag present > [ 4.651718] [J4D] flag not present(adding) > > [ 96.025668] [J4D] flag present > [ 100.130626] [J4D] flag present > [ 116.435436] [J4D] flag present > > I mostly just guessed at do_startup() being the place to set the magic > multiplier flag after it didn't stick in quirk in 8250_pci.c. Can you share `dmesg` and output of `lspci -nk -vv` on the machine with the kernel with patches applied and running? -- With Best Regards, Andy Shevchenko