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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 45AC0C282C3 for ; Tue, 22 Jan 2019 22:07:26 +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 C207520870 for ; Tue, 22 Jan 2019 22:07:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C207520870 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=telegraphics.com.au 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 43kjFl55dxzDqMV for ; Wed, 23 Jan 2019 09:07:23 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=telegraphics.com.au (client-ip=98.124.60.144; helo=kvm5.telegraphics.com.au; envelope-from=fthain@telegraphics.com.au; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=telegraphics.com.au Received: from kvm5.telegraphics.com.au (kvm5.telegraphics.com.au [98.124.60.144]) by lists.ozlabs.org (Postfix) with ESMTP id 43kjCn3ZTrzDqJX for ; Wed, 23 Jan 2019 09:05:41 +1100 (AEDT) Received: from localhost (localhost.localdomain [127.0.0.1]) by kvm5.telegraphics.com.au (Postfix) with ESMTP id 085AC29B17; Tue, 22 Jan 2019 17:05:35 -0500 (EST) Date: Wed, 23 Jan 2019 09:06:30 +1100 (AEDT) From: Finn Thain To: Greg Kroah-Hartman Subject: Re: [PATCH v9 00/22] Re-use nvram module In-Reply-To: <20190122092234.GA15813@kroah.com> Message-ID: References: <20190122092234.GA15813@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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: Michael Schmitz , linux-fbdev@vger.kernel.org, Arnd Bergmann , "Martin K. Petersen" , Bartlomiej Zolnierkiewicz , "James E.J. Bottomley" , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-scsi@vger.kernel.org, linux-m68k@lists.linux-m68k.org, Geert Uytterhoeven , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, Joshua Thompson Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, 22 Jan 2019, Greg Kroah-Hartman wrote: > On Tue, Jan 15, 2019 at 03:18:56PM +1100, Finn Thain wrote: > > The "generic" NVRAM module, drivers/char/generic_nvram.c, implements a > > /dev/nvram misc device. This module is used only by 32-bit PowerPC > > platforms. > > > > The RTC "CMOS" NVRAM module, drivers/char/nvram.c, also implements a > > /dev/nvram misc device. This module is now used only by x86 and m68k > > thanks to commit 3ba9faedc180 ("char: nvram: disable on ARM"). > > > > The "generic" module cannot be used by x86 or m68k platforms because it > > cannot co-exist with the "CMOS" module. One reason for that is the > > CONFIG_GENERIC_NVRAM kludge in drivers/char/Makefile. Another reason is > > that automatically loading the appropriate module would be impossible > > because only one module can provide the char-major-10-144 alias. > > > > A multi-platform kernel binary needs a single, generic module. With this > > patch series, drivers/char/nvram.c becomes more generic and some of the > > arch-specific code gets moved under arch/. The nvram module is then > > usable by all m68k, powerpc and x86 platforms. > > > > This allows for removal of drivers/char/generic_nvram.c as well as a > > duplicate in arch/powerpc/kernel/nvram_64.c. By reducing the number of > > /dev/nvram char misc device implementations, the number of bugs and > > inconsistencies is also reduced. > > > > This approach reduces inconsistencies between PPC32 and PPC64 and also > > between PPC_PMAC and MAC. A uniform API has benefits for userspace. > > > > For example, some error codes for some ioctl calls become consistent > > across PowerPC platforms. The uniform API can potentially benefit any > > bootloader that works across the various platforms having XPRAM > > (e.g. Emile). > > > > This patch series was tested on Atari, Mac, PowerMac (both 32-bit and > > 64-bit) and ThinkPad hardware. AFAIK, it has not yet been tested on > > pSeries or CHRP. > > > > I think there are two possible merge strategies for this patch series. > > The char misc maintainer could take the entire series. Alternatively, > > the m68k maintainer could take patches 1 thru 16 (though some of these > > have nothing to do with m68k) and after those patches reach mainline > > the powerpc maintainer could take 17 thru 22. > > I just took the whole series, thanks for doing this, looks good. > Thanks, Greg. I haven't seen any acks from powerpc maintainers yet... -- > greg k-h >