From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 2E9BE2E612D for ; Tue, 2 Sep 2025 09:42:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756806136; cv=none; b=Mf/od9UHUUcrzNfzN813N+PcFOXQ60JWNl7GrV8aM/wLnEFpBbVFll8V2MU2of8BVGDcIBhZ4qgJkT5tcDLwCbDDBWfBoe/moUM+i73a6+xgjnw4RKGkfFpM7IJI6AHanDELVeIrhv6zfvph3kBpQS3Y9ln7/xGw/n0PomG6Ofk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756806136; c=relaxed/simple; bh=0r3Kbl66SOPlH3J9OpigscsrmnOrTPBzkofO/1BNk4E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=f1Y9b52BcXj0IPGQbamOIsNbNkUjomr2s5Plx0EsL5eUgeMaJOY71onIyCNP+8Z6Fbn0tNcZwxXkkX+J8oteI5TdOnmBbiQv7GOrk90Mxhu9n5BJaGJd3i+RDWUkgHSsJ3jqLf7QrRwbY5B9lbFAp8idsAgMtxfPkZG7heRguwc= 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=TUGh9MOP; arc=none smtp.client-ip=198.175.65.14 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="TUGh9MOP" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1756806135; x=1788342135; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=0r3Kbl66SOPlH3J9OpigscsrmnOrTPBzkofO/1BNk4E=; b=TUGh9MOP440WK0Ql2JALw5iCI4a5VnOJJcFy2MnzOCuOCvCnfePz/b3C QlCiZfCnw7sZZr8eLyzV9EsBy4fgyrzmm5raODHP7Lx7zyLCYei8bVffk +nT/nIB2LTRgzgdhB6865DMvIePcAvp3+3XGFEm8WMUwgtbfHPM2PGaC0 NPvbsfShthoWfPLWStjfWp5vijWpUXHYX9U/+52pbAo0BftCsaK1HIdQQ tNxrmePKkolrrRJJ5lQcSEtmsp2LILrHj7hoUHze4XCdy+TbZbaYu45QI mnxYlV8UjBzNkJa/THgMsNNAzPX3mNSvFSPkGxz7ENXCIa0QIPE2hz2gd Q==; X-CSE-ConnectionGUID: 4Z1wT65YTMOXbzSNvgqgMQ== X-CSE-MsgGUID: MqeEZH+rRm27HGfq2ck2jw== X-IronPort-AV: E=McAfee;i="6800,10657,11531"; a="62900819" X-IronPort-AV: E=Sophos;i="6.17,312,1747724400"; d="scan'208";a="62900819" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Sep 2025 02:42:14 -0700 X-CSE-ConnectionGUID: G1gZxVEnTV+SPbaUE/+9hA== X-CSE-MsgGUID: 4Vml7+MWTBO0NclOcEoSFQ== X-ExtLoop1: 1 Received: from smile.fi.intel.com ([10.237.72.52]) by fmviesa003.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Sep 2025 02:42:12 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.98.2) (envelope-from ) id 1utNWj-0000000Aeom-1t4L; Tue, 02 Sep 2025 12:42:09 +0300 Date: Tue, 2 Sep 2025 12:42:09 +0300 From: Andy Shevchenko To: Adrian =?utf-8?Q?Barna=C5=9B?= Cc: Hans de Goede , Mauro Carvalho Chehab , Sakari Ailus , Andy Shevchenko , Greg Kroah-Hartman , Dan Carpenter , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev Subject: Re: [RFC] staging: media: atomisp: Simplyfy masking bit logic Message-ID: References: <20250902073841.2338568-1-abarnas@google.com> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250902073841.2338568-1-abarnas@google.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Tue, Sep 02, 2025 at 07:38:40AM +0000, Adrian Barnaś wrote: > Simplified masking logic in pci/hive_isp_css_common/host/vmem.c. ... > --- > > I have tested this change on whole range of *valid* inputs, and it gives > the same results as before, but this function seems to be little > counter-intuitive as far as start is a (bit index) but end is > (bit index + 1). We can't change it without changing the callers at the same time. So, better to change just helpers and later on, if working, change the semantics of the parameter. > --- ... > subword(hive_uedge w, unsigned int start, unsigned int end) > { > - return (w & (((1ULL << (end - 1)) - 1) << 1 | 1)) >> start; > + return (w & __GENMASK_ULL(end-1, 0)) >> start; Why __ variant? > } ... > inv_subword(hive_uedge w, unsigned int start, unsigned int end) > { > - return w & (~(((1ULL << (end - 1)) - 1) << 1 | 1) | ((1ULL << start) - 1)); > + return w & (~__GENMASK_ULL(end-1, start)); > } Ditto. -- With Best Regards, Andy Shevchenko