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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable 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 95AF1C3F2C6 for ; Sat, 29 Feb 2020 23:14:47 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5136E24672 for ; Sat, 29 Feb 2020 23:14:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5136E24672 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=buserror.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48VMgS5KfBzDrLv for ; Sun, 1 Mar 2020 10:14:44 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=buserror.net (client-ip=165.227.176.147; helo=baldur.buserror.net; envelope-from=oss@buserror.net; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=buserror.net Received: from baldur.buserror.net (baldur.buserror.net [165.227.176.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48VMdn1XbmzDqZH for ; Sun, 1 Mar 2020 10:13:17 +1100 (AEDT) Received: from [2601:449:8480:af0:12bf:48ff:fe84:c9a0] by baldur.buserror.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1j8BI4-0002LE-3Z; Sat, 29 Feb 2020 17:13:01 -0600 Message-ID: From: Scott Wood To: =?UTF-8?Q?=E7=8E=8B=E6=96=87=E8=99=8E?= Date: Sat, 29 Feb 2020 17:12:58 -0600 In-Reply-To: References: Organization: Red Hat Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2601:449:8480:af0:12bf:48ff:fe84:c9a0 X-SA-Exim-Rcpt-To: wenhu.wang@vivo.com, wenhu.pku@gmail.com, galak@kernel.crashing.org, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, trivial@kernel.org, harninder.rai@nxp.com X-SA-Exim-Mail-From: oss@buserror.net Subject: Re: Re: [PATCH] powerpc/Kconfig: Make FSL_85XX_CACHE_SRAM configurable X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on baldur.buserror.net) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rai Harninder , trivial@kernel.org, linux-kernel@vger.kernel.org, wangwenhu , Paul Mackerras , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, 2020-01-21 at 14:38 +0800, 王文虎 wrote: > 发件人：Scott Wood > 发送日期：2020-01-21 13:49:59 > 收件人："王文虎" > 抄送人：wangwenhu ,Kumar Gala ,B > enjamin Herrenschmidt ,Paul Mackerras < > paulus@samba.org>,Michael Ellerman , > linuxppc-dev@lists.ozlabs.org,linux-kernel@vger.kernel.org, > trivial@kernel.org,Rai Harninder > 主题：Re: [PATCH] powerpc/Kconfig: Make FSL_85XX_CACHE_SRAM configurable>On > Tue, 2020-01-21 at 13:20 +0800, 王文虎 wrote: > > > From: Scott Wood > > > Date: 2020-01-21 11:25:25 > > > To: wangwenhu ,Kumar Gala < > > > galak@kernel.crashing.org>, > > > Benjamin Herrenschmidt ,Paul Mackerras < > > > paulus@samba.org>,Michael Ellerman , > > > linuxppc-dev@lists.ozlabs.org,linux-kernel@vger.kernel.org > > > Cc: trivial@kernel.org,wenhu.wang@vivo.com,Rai Harninder < > > > harninder.rai@nxp.com> > > > Subject: Re: [PATCH] powerpc/Kconfig: Make FSL_85XX_CACHE_SRAM > > > configurable>On Mon, 2020-01-20 at 06:43 -0800, wangwenhu wrote: > > > > > From: wangwenhu > > > > > > > > > > When generating .config file with menuconfig on Freescale BOOKE > > > > > SOC, FSL_85XX_CACHE_SRAM is not configurable for the lack of > > > > > description in the Kconfig field, which makes it impossible > > > > > to support L2Cache-Sram driver. Add a description to make it > > > > > configurable. > > > > > > > > > > Signed-off-by: wangwenhu > > > > > > > > The intent was that drivers using the SRAM API would select the > > > > symbol. What > > > > is the use case for selecting it manually? > > > > > > > > > > With a repository of multiple products(meaning different defconfigs) and > > > multiple > > > developers, the Kconfigs of the Kernel Source Tree change frequently. So > > > the > > > "make menuconfig" > > > process is needed for defconfigs' re-generating or updating for the > > > complexity of dependencies > > > between different features defined in the Kconfigs. > > > > That doesn't answer my question of how the SRAM code would be useful other > > than to some other driver that uses the API (which would use > > "select"). There > > is no userspace API. You could use the kernel command line to configure > > the > > SRAM but you need to get the address of it for it to be useful. > > > > Like you've asked below, via /dev/mem or direct calling within the Kernel. > And they are not submitted yes, under development. If they are calling within the kernel, then whatever driver that is should select FSL_85XX_CACHE_SRAM. Directly accessing /dev/mem without any way for the kernel to advertise where it is or which parts of SRAM are available for use sounds like a bad idea. -Scott