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 A71B9C00A89 for ; Fri, 30 Oct 2020 13:47:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 517AD2076E for ; Fri, 30 Oct 2020 13:47:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726259AbgJ3Nrr (ORCPT ); Fri, 30 Oct 2020 09:47:47 -0400 Received: from mga04.intel.com ([192.55.52.120]:33881 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725939AbgJ3Nrr (ORCPT ); Fri, 30 Oct 2020 09:47:47 -0400 IronPort-SDR: kat6Ku4RuaPmKkOgjtlLqQRRQcQJ31XHJGWuhGoT/IWgcfbAxpi2DxErJxX6tDyHhrSGmqaoU5 HbB3Gf2ygITQ== X-IronPort-AV: E=McAfee;i="6000,8403,9789"; a="166020660" X-IronPort-AV: E=Sophos;i="5.77,433,1596524400"; d="scan'208";a="166020660" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2020 06:47:47 -0700 IronPort-SDR: zoUKo1FtT17ECLW2HKOd9eWzcHCd2YY0wbjYcv8h0/wYHerjM+FAAWC/qAJyeFl9EYDPWNRRvA xP3IETLCx2TA== X-IronPort-AV: E=Sophos;i="5.77,433,1596524400"; d="scan'208";a="319324274" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2020 06:47:24 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1kYUlW-002OC8-VT; Fri, 30 Oct 2020 15:48:26 +0200 Date: Fri, 30 Oct 2020 15:48:26 +0200 From: Andy Shevchenko To: alberto.vignani@fastwebnet.it Cc: support3@ftdichip.com, kuba@mareimbrium.org, johan@kernel.org, linux-usb@vger.kernel.org Subject: Re: BUG Found, was: USB-Serial FT4232H unusable with kernel 5.9.x Message-ID: <20201030134826.GP4077@smile.fi.intel.com> References: <21357769.49031603989896975.JavaMail.root@pr006msr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <21357769.49031603989896975.JavaMail.root@pr006msr> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Oct 29, 2020 at 05:44:56PM +0100, alberto.vignani@fastwebnet.it wrote: > By bisecting the regression I found that the FT4232 was only an innocent bystander. The real culprit was the PCIe-USB adapter that stopped sending interrupts (or sent wrong interrupts) in kernel 5.9. I have just removed the whole patch and my system is working again as in 5.8.I hope that someone will revise this patch considering that the Pericom PI7C9X440SL is affected by it. Thank you for the report! Can you share output of % lspci -vvv -nk -s # where is a slot of PCIe USB for working and non-working cases? > Here's the commit responsible: > commit 306c54d0edb6 usb: hcd: Try MSI interrupts on PCI devices This commit per se should not affect devices which rightfully announce MSI support. It is possible that I have missed something or above mentioned device is not MSI compatible. Btw, can this PCIe-USB be connected to completely different motherboard / machine for a testing purposes? It might be that PCI host bridge is not friendly with the device or other way around. ... > With 5.9 I noticed that these delays are dependent on how the ports are mapped t o linux devices:- if I remove the JTAG > quirk and allow all ports to be connected to ttyUSBs, there seems to > be no delay before the first message: 33 usec as in linux 5.8. Of course I cannot then configure the first two ports for JTAG (FTOpen fails). > - conversely, if I > remove the ftdi_sio module (with all ttyUSB devices) the initial delay > is even longer (7.6 seconds), and then the (slow) JTAG configuration s ucceeds. > Can someone confirm and investigate? Does the same happen with ST Micro Connect Lite? > And how can I debug this one? Can you also monitor /proc/interrupts for working and non-working cases? Simply share its contents as well. -- With Best Regards, Andy Shevchenko