From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (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 0077839A7F3; Tue, 3 Feb 2026 09:54:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770112484; cv=none; b=Fg8R4QgyoT+ZtGJXO7RKa2FffAcAbFxAhC0Mxy1V9GoM6ifHO76pP0fe40wUOazdrJwuDfbrFrX+346bNcrl8K1kHCC2pF1UK6fEoxcZabzxwtBXb3HzbmPT2WgLX43qieUDJoBnXoqj8evuAYI86uuSqaBMJo3hhUDKJei4nZk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770112484; c=relaxed/simple; bh=y5rSFPph6ZOlD8suEvnSJyWbUJlAwTCuj4psg7sVWiw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YX36sPNmZKuttknbelDPWVmltrNqff4aEevhEC+gkG+6pNA7XzaNaKJF7PFToktg59cIz07Emr8oVj4VuOpvDKIIoA85B+tI4DunNxzmMjDLxG2qsPTunj5BN+LTEHu2gpkFWgfCPnhsVU82D/fCyznHO2PCp7yV+mdNLkth04Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Upwx8GJy; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Upwx8GJy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1770112482; x=1801648482; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=y5rSFPph6ZOlD8suEvnSJyWbUJlAwTCuj4psg7sVWiw=; b=Upwx8GJygKukQdhxv89nkccHtL/31sfaTm+g4nBHywuh3T2Mr0Aav94b wCxAQgbm+U42W/SF6KVvBAHRnwe78VvEkzipuZp3ObWRgmNIPqublOR/q ETzpR9krQFNfzA1poSmXwXQ5O0/j5z3jmRM7mrvkO/BvLVohV9AL0ndD+ ECFdx5VPPGfK2J+iPnQekY93jcSzE4Qbyyaz7nTD/OPAZxYkhPA+bgdo1 0O/N/svjNT9eB2zeC45jmn1D86Tfpf5aWmWX6esSZSJCFiwjlc8IskKqY VSD8AyRqdK1AKa1pfAnqud0/Iqdqsa0aatZXTxhtpbj2/hRcANyq0mYtR w==; X-CSE-ConnectionGUID: SUVLI6LNQ1a1ofNO7cLs/A== X-CSE-MsgGUID: yxJQnjrtR0SEngQxwQX7wg== X-IronPort-AV: E=McAfee;i="6800,10657,11690"; a="73874403" X-IronPort-AV: E=Sophos;i="6.21,270,1763452800"; d="scan'208";a="73874403" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Feb 2026 01:54:41 -0800 X-CSE-ConnectionGUID: cFw4D0ydSwuPBfH+P3T/ag== X-CSE-MsgGUID: mHP/9pZkRNaGNPNM1nia2w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,270,1763452800"; d="scan'208";a="209817312" Received: from pgcooper-mobl3.ger.corp.intel.com (HELO localhost) ([10.245.245.99]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Feb 2026 01:54:38 -0800 Date: Tue, 3 Feb 2026 11:54:35 +0200 From: Andy Shevchenko To: Oleksij Rempel Cc: Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley , stable@vger.kernel.org, kernel@pengutronix.de, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, Andy Shevchenko , David Lechner , Nuno =?iso-8859-1?Q?S=E1?= , David Jander Subject: Re: [PATCH v4 01/13] iio: dac: ds4424: reject -128 RAW value Message-ID: References: <20260203093434.2548978-1-o.rempel@pengutronix.de> <20260203093434.2548978-2-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260203093434.2548978-2-o.rempel@pengutronix.de> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Tue, Feb 03, 2026 at 10:34:21AM +0100, Oleksij Rempel wrote: > The DS442x DAC uses sign-magnitude encoding, so -128 cannot be represented > in hardware (7-bit magnitude). > > Previously, passing -128 resulted in a truncated value that programmed > 0mA (magnitude 0) instead of the expected maximum negative current, > effectively failing silently. > > Reject -128 to avoid producing the wrong current. ... > case IIO_CHAN_INFO_RAW: > - if (val < S8_MIN || val > S8_MAX) > + if (val <= S8_MIN || val > S8_MAX) > return -EINVAL; I still consider using -127, 127 is better than type _MIN/_MAX. This is all due to '='. -- With Best Regards, Andy Shevchenko