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=-4.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 08F21C04EB8 for ; Mon, 10 Dec 2018 14:04:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDDD32086D for ; Mon, 10 Dec 2018 14:04:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="jHFFYrXP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BDDD32086D Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=ti.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727692AbeLJOEt (ORCPT ); Mon, 10 Dec 2018 09:04:49 -0500 Received: from fllv0016.ext.ti.com ([198.47.19.142]:36018 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727332AbeLJOEt (ORCPT ); Mon, 10 Dec 2018 09:04:49 -0500 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id wBAE4kkX018595; Mon, 10 Dec 2018 08:04:46 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1544450686; bh=kDwfUcEwteZlmv6r9xReHZQUOZQwOcxcNNHdieWYmys=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=jHFFYrXPH+Zsmv+V2JekSKBjkGcVedPiir9p2xsb4nloOTivY0XuLPKFd91cpH/aP VhU7wfZTcXo60ejYBRXHhPakw2Ge1sbTZP8rSCO0QayNm+gCMPnK4nFpy5Mz+rYjyV gYMNAQH35FRHoA5pzifJ40k33yZALQ6HWE+I7P1I= Received: from DFLE102.ent.ti.com (dfle102.ent.ti.com [10.64.6.23]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id wBAE4kAX074839 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 10 Dec 2018 08:04:46 -0600 Received: from DFLE112.ent.ti.com (10.64.6.33) by DFLE102.ent.ti.com (10.64.6.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1591.10; Mon, 10 Dec 2018 08:04:46 -0600 Received: from dlep32.itg.ti.com (157.170.170.100) by DFLE112.ent.ti.com (10.64.6.33) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_RSA_WITH_AES_256_CBC_SHA) id 15.1.1591.10 via Frontend Transport; Mon, 10 Dec 2018 08:04:46 -0600 Received: from [172.24.190.215] (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id wBAE4iEE014834; Mon, 10 Dec 2018 08:04:44 -0600 Subject: Re: [PATCH] mmc: sdhci-omap: Workaround errata regarding SDR104/HS200 tuning failures (i929) To: Ulf Hansson CC: Kishon , Linux Kernel Mailing List , "linux-mmc@vger.kernel.org" , Adrian Hunter References: <20181129190503.6040-1-faiz_abbas@ti.com> From: Faiz Abbas Message-ID: Date: Mon, 10 Dec 2018 19:37:31 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 10/12/18 7:15 PM, Ulf Hansson wrote: > On Mon, 10 Dec 2018 at 14:23, Faiz Abbas wrote: >> >> Hi Uffe, >> >> On 05/12/18 7:20 PM, Ulf Hansson wrote: >>> On Fri, 30 Nov 2018 at 06:53, Faiz Abbas wrote: >>>> >>>> Hi Kishon, >>>> >>>> On 30/11/18 10:10 AM, Kishon Vijay Abraham I wrote: >>>>> Hi Faiz, >>>>> >>>>> On 30/11/18 12:35 AM, Faiz Abbas wrote: >>>>>> Errata i929 in certain OMAP5/DRA7XX/AM57XX silicon revisions >>>>>> (SPRZ426D - November 2014 - Revised February 2018 [1]) mentions >>>>>> unexpected tuning pattern errors. A small failure band may be present >>>>>> in the tuning range which may be missed by the current algorithm. >>>>>> Furthermore, the failure bands vary with temperature leading to >>>>>> different optimum tuning values for different temperatures. >>>>>> >>>>>> As suggested in the related Application Report (SPRACA9B - October 2017 >>>>>> - Revised July 2018 [2]), tuning should be done in two stages. >>>>>> In stage 1, assign the optimum ratio in the maximum pass window for the >>>>>> current temperature. In stage 2, if the chosen value is close to the >>>>>> small failure band, move away from it in the appropriate direction. >>>>>> >>>>>> References: >>>>>> [1] http://www.ti.com/lit/pdf/sprz426 >>>>>> [2] http://www.ti.com/lit/pdf/SPRACA9 >>>>>> >>>>>> Signed-off-by: Faiz Abbas >>>>>> --- ... >>>>> >>>>> Can't we get thermal zone once during probe? >>>>> >>>> >>>> Tuning is also (ideally) supposed to happen only once per enumeration. >>>> Also it doesn't make sense to get a thermal zone for lower speed systems >>>> that won't do tuning. >>> >>> Currently sdhci-omap calls pm_runtime_get_sync() during probe, and >>> then keeps the host device runtime resumed until ->remove() is called >>> on it. I assume you are going to change that, at some point!? >>> >>> In other words, what will happen to the host device when it becomes >>> runtime suspended? Is re-tuning needed when it gets runtime resumed, >>> which is the case for many other sdhci variants? >> >> There are no plans to support runtime_suspend()/resume() any time in the >> near future. If its ok with you, I would like to get this patch in >> without any changes. We can change it in case a need for >> runtime_suspend()/_resume() does arise. > > Right, I am okay with that. Due to recent changes to sdhci-omap > $subject patch doesn't apply, can you please rebase!? > > Additionally, I realized that we should fold in patch updating the DT > doc for sdhci-omap, adding the property for the thermal zone. I > regards to that, I am wondering if "cpu_thermal", is really the > correct name of the zone. The point is, I am guessing the zone could > change along with the SoCs/platforms. > As you have probably noticed, we are introducing a new driver (sdhci_am654) for newer platforms. I don't foresee using sdhci-omap driver with any other platforms. In case we do use it, we can add the dt property at that point of time and default to "cpu_thermal" to maintain dt compatibility. Will rebase and send v2 if you are ok with above. Thanks, Faiz