From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lithops.sigma-star.at (mailout.nod.at [116.203.167.152]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 76B1F189B84; Sat, 29 Nov 2025 15:18:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=116.203.167.152 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764429522; cv=none; b=es/tuozjUL21kLlBQy3pxcYOkCufMrIhqa+odegI3mzZitBVtttcqCvFvo7oET1HFe78urooEgJ15keZvxpa52qm3KTOUqB//zAoeBOBH1qLS/eiJQCeLKIdt7V6Sm7B5O7sjJU+uaOgP908vKivCKM+hlDmWkUA1rTa/gc/huw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764429522; c=relaxed/simple; bh=J3cipEaybpHTdwIhJrqAyxsTqM/AiUJ4FSIorDQrTAQ=; h=Date:From:To:Cc:Message-ID:In-Reply-To:References:Subject: MIME-Version:Content-Type; b=TmKzk80ac0jk/jTkWWA4bbr02jjnJQy8kYQjSQ3Uf0nU1t1SkppOf6KHqXvW7fv/yqh7ZqbVPHaV5rYtvBU0Hp5h7cJQ3PSlhuK957qUXR+9U59ooZ8GIRNK/dMX6ZDzJikkpowdkhPF56DfRKa71ZmdxLGmZA/RseTQsiEYeEU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=nod.at; spf=fail smtp.mailfrom=nod.at; arc=none smtp.client-ip=116.203.167.152 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=nod.at Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nod.at Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 5A1902ABFDC; Sat, 29 Nov 2025 16:18:37 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 3-3q397sa7M9; Sat, 29 Nov 2025 16:18:36 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id BDF7111C05C; Sat, 29 Nov 2025 16:18:35 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id SpTLUuCX8Row; Sat, 29 Nov 2025 16:18:35 +0100 (CET) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id 8886F2C14AA; Sat, 29 Nov 2025 16:18:35 +0100 (CET) Date: Sat, 29 Nov 2025 16:18:35 +0100 (CET) From: Richard Weinberger To: Andreas Kemnade Cc: linux-kernel , linux-omap@vger.kernel.org, devicetree , Arnd Bergmann , Lee Jones , dakr@kernel.org, "Rafael J. Wysocki" , Greg Kroah-Hartman , Mark Brown , tony@atomide.com, rogerq@kernel.org, khilman@baylibre.com, aaro koskinen , Conor Dooley , Krzysztof Kozlowski , robh Message-ID: <253085958.4428.1764429515315.JavaMail.zimbra@nod.at> In-Reply-To: <20251129153644.333498f1@kemnade.info> References: <20251129142042.344359-1-richard@nod.at> <20251129153644.333498f1@kemnade.info> Subject: Re: [PATCH 0/4] Add tooling to disable debugfs on OMAP based systems Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF144 (Linux)/8.8.12_GA_3809) Thread-Topic: Add tooling to disable debugfs on OMAP based systems Thread-Index: ice++2tPGd+aipsod6lFeidVZflPZw== ----- Urspr=C3=BCngliche Mail ----- > Von: "Andreas Kemnade" > it is usually not about individual registers, but about accessing > unpowered devices/modules, >=20 > so it is probably more the logic like: >=20 > if (pm_runtime_is_suspended(regmap->device)) >=09-EACCESS; >=20 > Try to play around with on >power/control in sysfs. Well the that regmap is owned by the syscon mfd. And in case of CTRL_MODULE_CORE only accessing some reserved registers caus= es an abort. For registers like dsp_system@40d00000 it's maybe indeed due to an unpowere= d module. I'll double check that. =20 >> So, add tooling to allow disabling debugfs access to such dangerous regi= sters. >> Splitting the register map definitions in the device tree seemed less pr= actical >> to >> me since it would unnecessarily make the device trees more complicated. >>=20 > So is it really a description of the hardware? Maybe there are some speci= al > cases, too. IMHO, "There are problematic registers, don't blindly mess with them" is a = description of the hardware. Thanks, //richard