From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=198.175.65.15 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792957289; b=HOzjZhoZDiw9CNY9SBWmeaJSHBH05kJT+gkWTTXtVgT6wJdkgY/H1GJ3kUJQkDlJuur4 eUgr+NN3IoIQjEtCsijWwHd0JC/7/ENZBCreDU+hZNcPYgIQLeRjryQpCfgh+EvYY86l2 0t8ai2qxLtoKxyugTJ0zdTGkw829inrsP5fdTaJk0oVxj5OpgspIwxiMDTENQlrWZuarv xKzlJWnHN6OJv+2sM3XmqnmvCGmHP8mQADjlYIJfj3F48ZvQ1H4856OWIUeXcz6Z02NiM 7OghG6deVqlNEKoMHOr129gnly5C+t3HUJffvTq70lKcSnuMAf3TmfgReGa6iYqenjw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792957289; h=DMARC-Filter:DKIM-Signature:X-CSE-ConnectionGUID:X-CSE-MsgGUID: X-IronPort-AV:X-IronPort-AV:Received:X-CSE-ConnectionGUID: X-CSE-MsgGUID:X-ExtLoop1:X-IronPort-AV:Received:Date:From:To:Cc: Subject:Message-ID:References:MIME-Version:Content-Type: Content-Disposition:In-Reply-To:Organization; bh=loWA2r/IE4nsDNCChsBycXYC/X66Yw4ZxZ+0xX/WqkI=; b=vmmgIC+c6oSx5KYCKJ3uKu9+F9XRad3W1lcqC1aJ07TUo8Kde+TZOdN0IgJUyCrjH+nj SF55d2DXykDsNXf9eLWA7oTbjrZj4oGJ6+SQh4XH2aQfCI/4yjzGu+fDkO8kFgJwGCKfA nKSOWS/IwF6JucV+R9MrEBZKLoE8cPuFW3ANTsNIH1JdHPdHLfhQhLw26+V1Ks644Afql McNEP02tAj/U1xFmbYxizOoKQIW7J7EMXy4Cbvu2ARLcKjQ0mDYNZlOw60Gl73zgdlI4A maSDGXQUlzLVc/tbLY1XCAmI989X7zL7Ja6QXaiclYLx1F3Q03aPAQQqQX0wGSzU7Fg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=TevI6izW; arc=none smtp.remote-ip=198.175.65.15 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8D15606A31A; Sun, 25 Oct 2026 19:41:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org A8D15606A31A 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, unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=TevI6izW DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1792957287; x=1824493287; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=EccOnYd2UQC7zr91/Q2wYbVks3BuQI9mfWlB2SLQG6A=; b=TevI6izW2gabiZUVyiI8VMV5dAoWo1/I5gY0xnKzC/6nUqT7xD2KlQ9m lCQ2X90h6CducPWljQDLmvosM8NEy5Ot7gyxxQxZhT9/Xo0adMNBK8s1q GoYmgXepQoFY6XPdqHExQBYA635H+hnQP9xCtOu8KMEcrrJ8/HW3cRvNR GpnCfKEgsYHIbeMbzz9TwwrXIJH7hsUGKxTVT+lYNiWC/2ZgStijogkfD LFzjo3H7BpR1+8LS2UnDDcn1geXaJy/w2zekP3Myvj+rXmAdc8Kwuw7u5 gN5g0tnKhsLRGIVG4dzkrPIHnp4sVwY9xp1YaO2ujLLaCiy6boXk+GDDq g==; X-CSE-ConnectionGUID: GMOME7CPRNCoTuMSVD5pQw== X-CSE-MsgGUID: GYdDt9sRQD+em3fjKLSlNA== X-IronPort-AV: E=McAfee;i="6800,10657,11946"; a="1631079" X-IronPort-AV: E=Sophos;i="6.27,178,1787036400"; d="scan'208";a="1631079" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2026 12:41:27 -0700 X-CSE-ConnectionGUID: EB5OyIlpTDW636+Y+sVf6g== X-CSE-MsgGUID: nXCi9rJqTa2WEOSuV5/d7w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,178,1787036400"; d="scan'208";a="4221341" Received: from hrotuna-mobl2.ger.corp.intel.com (HELO localhost) ([10.245.245.10]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2026 12:41:26 -0700 Date: Sun, 25 Oct 2026 21:41:23 +0200 From: Andy Shevchenko To: Victor Chernyakin Cc: Jonathan Cameron , David Lechner , Nuno =?iso-8859-1?Q?S=E1?= , Andy Shevchenko , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/3] iio: add IIO_VAL_DECIMAL64_{ATTO,ZEPTO,YOCTO} formats Message-ID: References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Sun, Oct 25, 2026 at 12:48:04AM -0500, Victor Chernyakin wrote: > The highest-precision format IIO has right now is IIO_VAL_DECIMAL64_FEMTO, > which gives 15 decimal digits of precision after the decimal point. This > is not enough for the upcoming TI FDC1004 driver, which needs 22 digits > of precision to exactly express its scale value. This patch adds higher- > precision formats, up to IIO_VAL_DECIMAL64_YOCTO (24 digits of precision). ... > +/* An abs() function that doesn't have undefined behavior for LLONG_MIN. */ Can you elaborate how so? > +static inline u64 abs_s64_no_overflow(s64 x) > +{ > + return x < 0 ? -(u64)x : (u64)x; > +} So, the trick you use is to update the type from signed to unsigned. '-' operator is always defined on unsigned types and produces modulo results in case the representation requires more bits than type has. FWIW, it's not MISRA-compliant :-) -- With Best Regards, Andy Shevchenko