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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B5235C2D0F6 for ; Tue, 12 May 2020 18:47:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 945A820673 for ; Tue, 12 May 2020 18:47:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="GTrAAg1h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726890AbgELSr0 (ORCPT ); Tue, 12 May 2020 14:47:26 -0400 Received: from lelv0142.ext.ti.com ([198.47.23.249]:55178 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726465AbgELSrZ (ORCPT ); Tue, 12 May 2020 14:47:25 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 04CIl0aH042905; Tue, 12 May 2020 13:47:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1589309220; bh=gdpZbVGnmu82Ltylj7zMGAjghfqs8C0XbDqrJcvjIUw=; h=Date:From:To:CC:Subject:References:In-Reply-To; b=GTrAAg1hJh7itOcW4SLu7lNpvXjddphXZysRjzEGFdlWjJXVRzwSncAD1hGESqoOq Yqx1WqS6Om6TRq4h94nigWX4VYc7/sUadEfEmgQ1OEUYxPV/nkFZurLYx+A6PIN0DO aB9Jjte/G2GkHBhyp1KqKrwyEGu8J6jJxMvMBxdg= Received: from DFLE109.ent.ti.com (dfle109.ent.ti.com [10.64.6.30]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 04CIl0WC011391 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 12 May 2020 13:47:00 -0500 Received: from DFLE109.ent.ti.com (10.64.6.30) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Tue, 12 May 2020 13:47:00 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Tue, 12 May 2020 13:47:00 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 04CIkxg4112061; Tue, 12 May 2020 13:46:59 -0500 Date: Wed, 13 May 2020 00:16:58 +0530 From: Pratyush Yadav To: CC: , , , , , , , , , , , , Subject: Re: [PATCH v4 00/16] mtd: spi-nor: add xSPI Octal DTR support Message-ID: <20200512184656.ksudjyeqbwv6jze6@ti.com> References: <20200424184410.8578-1-p.yadav@ti.com> <144878625.o7txgtY6sz@192.168.0.120> <49abc8f3-5bb5-bc6d-b2ec-f14b115c58dc@ti.com> <2352513.UHBGRE98Z5@192.168.0.120> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <2352513.UHBGRE98Z5@192.168.0.120> User-Agent: NeoMutt/20171215 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 On 12/05/20 11:29AM, Tudor.Ambarus@microchip.com wrote: > Hi, Vignesh, > > > > The software reset procedure can't protect you from unexpected > > > resets, but > > > the hardware with its optional reset pin can. Pratyush to confirm. > > > > > > cut > > > > > >>> Not recovering from unexpected resets is unacceptable. One should always > > >>> prefer option 1/ and condition the entering in 2-2-2, 4-4-4 and 8-8-8 > > >>> with > > >>> the presence of the optional RESET pin. > > >> > > >> Totally agree with you on that one, but we know what happens in > > >> practice... > > > > > > What I proposed is to condition the entering in the state-full modes with > > > the presence of the optional RESET pin. We would introduce an optional > > > device tree property for the RESET pin. If hardware doesn't implement the > > > optional RESET# signal, then we will not enter in the state-full modes. > > > > Are you asking for dedicated SW controllable reset line or just an > > indication from DT that OSPI reset line is connected to board level > > soft/hard reset lines? > > I don't see a need for the reset line to be SW controllable, a simple > indication from the device tree should be enough. We already have the property "broken-flash-reset". Should we re-use it or should we have a opt-in property instead of an opt-out one? > > > > Mandating SW controllable RESET line is bit of a stretch IMO... Board > > design may not allow wasting dedicated pin due to lack of GPIOs perhaps.. > > > > For eg.: TI EVM has OSPI reset line connected to board level reset out. > > This ensures any soft/warm/hard CPU reset will trigger OSPI Flash reset, > > but there is no SW control that allows OSPI flash alone to be reset. > > Isn't such a reset mechanism sufficient? > > > > I think it is, yes. -- Regards, Pratyush Yadav Texas Instruments India