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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0C139D3901B for ; Wed, 14 Jan 2026 21:06:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=za0fpDkWlNRgAE2HAgbjpp1kpbvg5WT+0bRe4U+oU+o=; b=PpMuGSEwnyIvGPokwahY0/fxZ5 OFWy4W3M91ndC8GZDm+/Nk8+hIK074EXhYcLHDxSHErpUncTFdk3eVyQifv4sohx+nhiKT2ZJ/fbX mGjLfi1na+fQ8xSTMsRgh5FmHFYVeVyJojRqZ/SAbAWFT+IpqSKnO25uUSjE+OKCme1BN5BHIGlm4 yKb5PK9+q9/TotKdbwsU42UTXx3WwUE2Ld3IQzDQZdXB7TkF/palrbYrUeyHeR3MinT7iZiyjg4x1 8Xfq3PJF46kahc2kR6QELxSFIYJhw6iTO3H68B9OV9XAfU7ij81XRY7pMotYtKFHOt65TIvoy1M7+ wdypJMgA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vg84J-0000000Aj3H-2WPb; Wed, 14 Jan 2026 21:06:19 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vg84E-0000000Aj2k-3Hwn for linux-arm-kernel@lists.infradead.org; Wed, 14 Jan 2026 21:06:16 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8B0951515; Wed, 14 Jan 2026 13:06:05 -0800 (PST) Received: from bogus (unknown [10.57.49.158]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 172B23F59E; Wed, 14 Jan 2026 13:06:09 -0800 (PST) Date: Wed, 14 Jan 2026 21:06:06 +0000 From: Sudeep Holla To: Neil Armstrong Cc: Satya Durga Srinivasu Prabhala , Mark Rutland , Sudeep Holla , Lorenzo Pieralisi , linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, trilok.soni@oss.qualcomm.com Subject: Re: [PATCH] firmware: smccc: default ARM_SMCCC_SOC_ID to disabled Message-ID: References: <20260112-disable_smccc_soc_id-v1-1-a5bee24befb4@oss.qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260114_130615_238401_04C90C1E X-CRM114-Status: GOOD ( 27.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jan 14, 2026 at 06:12:29PM +0100, Neil Armstrong wrote: > On 1/13/26 07:24, Satya Durga Srinivasu Prabhala wrote: > > The ARM SMCCC SoC ID driver is currently enabled by default and publishes > > SMCCC-provided SoC identification into /sys/bus/soc/devices/socX/*. > > > > On platforms where a vendor SoC driver already exposes widely-consumed > > attributes (e.g. Qualcomm socinfo [1]), enabling the SMCCC driver changes > > the format of /sys/devices/soc0/soc_id (e.g. "jep106:XXYY:ZZZZ" instead > > of a vendor logical ID like "519") and breaks existing userspace consumers. > > > > Flip the default of CONFIG_ARM_SMCCC_SOC_ID from y to n. Platforms that > > prefer SMCCC over a vendor driver can explicitly enable it. > > > > This avoids unexpected format changes and keeps the generic SoC sysfs > > stable on systems that rely on vendor-specific identification. > > > > [1] > > Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/soc/qcom/socinfo.c > > > > Signed-off-by: Satya Durga Srinivasu Prabhala > > --- > > drivers/firmware/smccc/Kconfig | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/firmware/smccc/Kconfig b/drivers/firmware/smccc/Kconfig > > index 15e7466179a6..f830d11ebdca 100644 > > --- a/drivers/firmware/smccc/Kconfig > > +++ b/drivers/firmware/smccc/Kconfig > > @@ -18,8 +18,11 @@ config HAVE_ARM_SMCCC_DISCOVERY > > config ARM_SMCCC_SOC_ID > > bool "SoC bus device for the ARM SMCCC SOC_ID" > > depends on HAVE_ARM_SMCCC_DISCOVERY > > - default y > > + default n > > select SOC_BUS > > help > > Include support for the SoC bus on the ARM SMCCC firmware based > > platforms providing some sysfs information about the SoC variant. > > + Note: Several vendor platforms provide their own SoC information > > + drivers under drivers/soc/*. To avoid conflicting sysfs attribute > > + formats in /sys/devices/socX/*, this driver defaults to disabled. > > > > --- > > base-commit: b71e635feefc852405b14620a7fc58c4c80c0f73 > > change-id: 20260112-disable_smccc_soc_id-ed09ef4d777f > > > > Best regards, > > Disabling it by default impacts other platforms, the arm64 kernel is designed > to be generic and run on any platform with defconfig and from the same build, > please don't forget that. > > If you want to ship an arm64 kernel tailored for Qualcomm platforms, you're > allowed, and you're also allowed to disable ARM_SMCCC_SOC_ID. > Exactly! > The soc sysfs interface is designed to support multiple source of information, > from vendor (like qcom socinfo) and smccc ID. And this is well documented, > and pretty obvious... > Indeed, otherwise soc_device_register() would have failed for more than one calls to it if that was the design/intention. -- Regards, Sudeep