From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A6D93481 for ; Thu, 29 Jul 2021 14:20:57 +0000 (UTC) Received: by mail-pl1-f177.google.com with SMTP id e5so7151357pld.6 for ; Thu, 29 Jul 2021 07:20:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=F1MJS4je1Oiq7mhlbgvshdM+wBGyXHC/8oJzd/GZ1Bg=; b=Ow6fkhcPEh5V54oLfWWwMO7N3w8hOXvUHnRCEDo6zEciRgrCaJsWFsAcGnHwmh2vzD FPMisuZ3FNXTf1ixYZPueZXd8SlW0Sz5U+WAicNuv3cCxFOuib10hY1RfAbe25NVplGQ cFbNTcFvibLllrPwkX1NyOUGsfubqOt4JDVkl6QEMBEexnkifJfcBERFxqsXLxDQlC6C sWvxUebaqrJx4zyMhNnHramYFQuvyDG0DUp+CZ8TnJsj2WONURIPg4QNHM4xLMgwjz4d aQIxu9xpzTPCVDDZQL0Apsap6Nh+R7+Z0NH4Xj2u0w2G5KRLYVz10F7gqa8OYyYtCME9 Ig2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=F1MJS4je1Oiq7mhlbgvshdM+wBGyXHC/8oJzd/GZ1Bg=; b=JQGIgla2gTz3qIrAwD1/ER7q/Sl+COd4g1ChzwBruzQ33x3yimtJl4qf6Oynq1+qKt pMbpZcAFDRyhWFyG00gwpocOLb1oLQoZOz/KSfsT5muLm+Y0mnOfTU9k3RDZMz/fO0Df 1jAy8dIVFFmhOBOMF2KCN+1QaDx8uCxUEzbKueWxvt8izj8FmY1RueXf6haenMqTYR0w xRHpin2FlR56Zd6Wl541Z2Xui7VTVpdHMKaDnLaAvF9IWwGuJ3LOZxwOymOIP0ssqrJx tutSffsbLZOybQhn4wmD5bbFpVC3l8W4LpXsj9tvkPay06iVnumUG9WkbySJzZW/olpT s4vw== X-Gm-Message-State: AOAM532pPJdZSMfGOF9BY3QQGfT+PYUMWPTtiNU5cSWKdlXNmi9vr5I0 mQPcgWKGPMsJMBc0knGFb0E= X-Google-Smtp-Source: ABdhPJwJqoUiFy7YXuGI7xJHhZ4oqQidNFSSfrsgUMREpiAhvQS66r555cMNOfkEqZZH73MivZZI6w== X-Received: by 2002:a17:902:a9c3:b029:12c:31c7:9b81 with SMTP id b3-20020a170902a9c3b029012c31c79b81mr4901232plr.30.1627568456660; Thu, 29 Jul 2021 07:20:56 -0700 (PDT) Received: from ojas ([122.161.51.5]) by smtp.gmail.com with ESMTPSA id p3sm4091663pgi.20.2021.07.29.07.20.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Jul 2021 07:20:56 -0700 (PDT) Date: Thu, 29 Jul 2021 19:50:43 +0530 From: Ojaswin Mujoo To: Stefan Wahren Cc: Greg KH , nsaenz@kernel.org, dan.carpenter@oracle.com, phil@raspberrypi.com, linux-arm-kernel@lists.infradead.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] staging: vchiq: Set $CONFIG_VCHIQ_CDEV to be enabled by default Message-ID: <20210729142043.GA25192@ojas> References: <70d91b0482e19d7551d3258ea54c970c1b996317.1627495116.git.ojaswin98@gmail.com> <20210728200607.GB17046@ojas> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jul 28, 2021 at 10:21:41PM +0200, Stefan Wahren wrote: > Am 28.07.21 um 22:06 schrieb Ojaswin Mujoo: > > On Wed, Jul 28, 2021 at 08:45:55PM +0200, Greg KH wrote: > >> On Thu, Jul 29, 2021 at 12:07:16AM +0530, Ojaswin Mujoo wrote: > >>> Before this config was defined, the cdev used to be created > >>> unconditionally. When an earlier commit introduced this config, the > >>> default behavior was set to disabled, which might surprise some > >>> unsuspecting users. Hence, make this config default to 'Y' to be more > >>> backward consistent. > >>> > >>> Signed-off-by: Ojaswin Mujoo > >>> --- > >>> drivers/staging/vc04_services/Kconfig | 1 + > >>> 1 file changed, 1 insertion(+) > >>> > >>> diff --git a/drivers/staging/vc04_services/Kconfig b/drivers/staging/vc04_services/Kconfig > >>> index 63caa6818d37..2b70c37cdd09 100644 > >>> --- a/drivers/staging/vc04_services/Kconfig > >>> +++ b/drivers/staging/vc04_services/Kconfig > >>> @@ -23,6 +23,7 @@ if BCM2835_VCHIQ > >>> > >>> config VCHIQ_CDEV > >>> bool "VCHIQ Character Driver" > >>> + default y > >> > >> default y is only if the machine will not work without this option. > >> Is that the case here? If not, then please do not have this as the > >> default. > > Got it Greg. > > > > From my testing, the Raspberry Pi does seem to boot correctly without > > this although some userspace libraries might not work. > > > > Since the machine itself works, I guess I'll drop this patch. > > The idea is good, but the patch needs improvement :) > > Acceptable solution might be that BCM2835_VCHIQ selects VCHIQ_CDEV. Thanks for the suggestion, Stefan. So on testing with select, it seems like select defines a hard reverse dependency i.e if BCM2835_VCHIQ=y then VCHIQ_CDEV=y and it can't be set to n. Checking the Kconfig launguae doc, I found that we could use "imply" to define weak reverse dependencies, such that BCM2835_VCHIQ=y auto selects VCHIQ_CDEV=y but we can also change it back to n if required. I tested this out and it seems to work fine. I believe we can se imply here as it better suits the use case. Thank you, Ojaswin > > > > > Thank you! > > Ojaswin > >> thanks, > >> > >> greg k-h > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >