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=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 AE5B1C43381 for ; Wed, 6 Mar 2019 09:46:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84A71206DD for ; Wed, 6 Mar 2019 09:46:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729847AbfCFJqB (ORCPT ); Wed, 6 Mar 2019 04:46:01 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:36153 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729695AbfCFJqB (ORCPT ); Wed, 6 Mar 2019 04:46:01 -0500 Received: from kresse.hi.pengutronix.de ([2001:67c:670:100:1d::2a]) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1h1T7b-0006X3-3u; Wed, 06 Mar 2019 10:45:55 +0100 Message-ID: <1551865552.9298.24.camel@pengutronix.de> Subject: Re: Smarter Kconfig help From: Lucas Stach To: Russell King - ARM Linux admin , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Peng Hao , Mark Rutland , Andy Shevchenko , Greg Kroah-Hartman Date: Wed, 06 Mar 2019 10:45:52 +0100 In-Reply-To: <20190305173111.t3n6ycktht7kxuhq@shell.armlinux.org.uk> References: <20190305173111.t3n6ycktht7kxuhq@shell.armlinux.org.uk> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::2a X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Russell, Am Dienstag, den 05.03.2019, 17:31 +0000 schrieb Russell King - ARM Linux admin: > Guys, > > We need to be smarter when writing Kconfig help.  I'm just going > through updating my build trees with the results of 5.0 development, > and a number of the help texts are next to useless.  For example, > > PVPANIC - is this something that should be enabled for a host or > guest kernel?  Answer: you have to read the driver code to find out. > > IMX_IRQSTEER - which i.MX SoCs does this apply to?  The help text > just says: > >   "Support for the i.MX IRQSTEER interrupt multiplexer/remapper." > > which doesn't say which SoCs this should be enabled for - it turns > out that grepping for the driver's DT compatible string, none of > the 32-bit ARM cores have support for this, yet we still default > it to enabled there.  It seems the help text should at the very > least tell the user that this is not applicable to i.MX SoCs with > 32-bit ARM cores. > > I'm sure there's many other instances of this... I suspect that > it's caused by review concentrating mostly on the technical aspects > of the code and the Kconfig help text just gets forgotten about. > > Can we at least improve these two options please? While I totally agree that the irqsteer driver should only default Y on 64bit i.MX SoCs, I'm not really sure what to do about the Kconfig help text. Enumerating SoCs in the Kconfig of a IP block driver is always prone to get outdated. Just as the first example I've been able to come up with, the MMC_SDHCI_ESDHC_IMX help text says: "This selects the Freescale eSDHC/uSDHC controller support found on i.MX25, i.MX35 i.MX5x and i.MX6x.", while the same IP block is to be found on i.MX7 and various i.MX8. For the Kconfig user, who needs to decide if an option is relevant, outdated SoC information is probably just as bad as no information at all. Regards, Lucas