From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (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 754E7168B8; Fri, 9 Aug 2024 15:56:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723218963; cv=none; b=qT0uX0b4ZyCpLJIMPNezadvcy0nI7baGIx9AdT0u9nJWT9AlLSBdZ07Epy/BS2SlfUILxEtzceHwuguYV7rmTEXGPzZYsj8HgvJuE07Gor0OOG/AwWtEZKXmC/bMlmzdKQAqb0ykq1F4ous7dyfMT29pa4/chMcmVutxObN1Jiw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723218963; c=relaxed/simple; bh=OnZ/XKvESL+KOqBHUml6q9GBQ4whpdRFBOLSr7/OVvY=; h=From:Date:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=NlwRdSCvLJr47akMX515cFA4R8wceAd7zE/k+7J8Nb2UEdUciq/KchiaBR//8swlHhoqa3JwuMYeWg8scbgrKrkuUAuAW/pBcBA0DN2c8HC1V1fCVnhgQwLiHF0QOl8TK84Eugu1Qh72njcPAcOttYnyxC/xHKmZ1YM2zSJtCnw= 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=WgcvN8n5; arc=none smtp.client-ip=192.198.163.19 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="WgcvN8n5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1723218962; x=1754754962; h=from:date:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=OnZ/XKvESL+KOqBHUml6q9GBQ4whpdRFBOLSr7/OVvY=; b=WgcvN8n5niV8vkwTvdmxy5TGzFULXv0dH/OWueSXbu633YHC7pmBcxQq tcG/YD+qE7X1+zlWH/qbWfdEHfTXMKsrTxcOK4yCuLv03vay78f0O0z9r Bn1ch925bTvx56ULYmtcJ2QNY/ZR9L192KG7kXiSlLpT46wQAvGD8+F5B yx4al8+wE6sy2o2jKaRSCsIokV4qReTQTM/sHqlcoubnJ7SY9oWoxwLWr wEpXGftAFltlObZbZ6mbPV27YyAV95kC/KGiOQVIcNdUfypg8Z1LEIKiR Cuf2wMLzcI9YMSdhy1D3mLiXJKRgiiCK/pkMCItbDuD9yUrUzWOsm1Ees w==; X-CSE-ConnectionGUID: vnAbsRHZTQeHW9izcxw4EA== X-CSE-MsgGUID: ubDrxqUXTDeHqj7vsOB3RQ== X-IronPort-AV: E=McAfee;i="6700,10204,11159"; a="21056342" X-IronPort-AV: E=Sophos;i="6.09,276,1716274800"; d="scan'208";a="21056342" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Aug 2024 08:56:01 -0700 X-CSE-ConnectionGUID: ztPBdIXkTmKV62b/0Z5qhg== X-CSE-MsgGUID: qpvnwexlT4qMwbZTiOK9YA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,276,1716274800"; d="scan'208";a="62243814" Received: from ijarvine-desk1.ger.corp.intel.com (HELO localhost) ([10.245.245.119]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Aug 2024 08:55:59 -0700 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Fri, 9 Aug 2024 18:55:56 +0300 (EEST) To: "Maciej W. Rozycki" cc: Bjorn Helgaas , linux-pci@vger.kernel.org, LKML , Mika Westerberg Subject: Re: [PATCH 1/2] PCI: Clear LBMS on resume to avoid Target Speed quirk In-Reply-To: Message-ID: <42afa3ee-4429-90e4-9e98-18a0d30c0a3c@linux.intel.com> References: <20240129184354.GA470131@bhelgaas> 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="8323328-969202318-1723218956=:1401" This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-969202318-1723218956=:1401 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE On Fri, 9 Aug 2024, Maciej W. Rozycki wrote: > On Wed, 7 Feb 2024, Ilpo J=C3=A4rvinen wrote: >=20 > > > > > Because if it is constantly picking another speed, it would mean = you get=20 > > > > > LBMS set over and over again, no? If that happens 34-35 times per= second,=20 > > > > > it should be set already again when we get into that quirk becaus= e there=20 > > > > > was some wait before it gets called. > > > >=20 > > > > I'll see if I can experiment with the hardware over the next coupl= e of=20 > > > > days and come back with my findings. > > >=20 > > > Okay thanks. > >=20 > > One point I'd be very interested to know if the link actually comes up= =20 > > successfully (even if briefly) because this has large implications whet= her=20 > > the quirk can actually be invoked from the bandwidth controller code. >=20 > That was more than a couple of days, sorry about it. I have now been=20 > able to verify that LBMS keeps getting reasserted over and over again as= =20 > the device goes through the infinite link training dance. I haven't ever= =20 > observed the link to become active in the course. Here's a short log of= =20 > commands repeatedly entered at the command prompt: >=20 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5011 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5812 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5811 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5812 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5011 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5811 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5811 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5812 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5812 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5811 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5811 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5812 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5812 > # setpci -s 02:03.0 CAP_EXP+0x12.W > 5811 >=20 > As you can see the Link Training bit oscillates as I previously reported= =20 > and noted in the introduction to `pcie_failed_link_retrain', and also the= =20 > Current Link Speed field flips between 2.5GT/s and 5GT/s. Okay, thanks for testing. I suppose that test wasn't done in a busy loop=20 (it might not be easy capture very short link up state if there was any=20 such period when testing it by manually launching that command a few=20 times)? --=20 i. --8323328-969202318-1723218956=:1401--