From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (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 BB655344044; Fri, 17 Jul 2026 18:10:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784311803; cv=none; b=pD/FTb8YLtCkcZo7EiTQTokFdSUYRSv5Mvix+VDuvqrB1DOPwUe0mTv7fKu/bKDAjl8jstMsrlWAR+5TTZHs3HH36iwYA+d2lk9GSajZlk5LGJauUVh6ARKD0a3jkGmbV0PlyvtTTIcUzr17Z9F/JiipoYb894v7fKXFpMtFjGg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784311803; c=relaxed/simple; bh=SIkNe2VoDIMYydSotihO3ya17IET6rA23vsy2BTnTsE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sX85HxaE2/nYAUtJaIgRtbBrD6AevfbK6P3X/UJykvKg8gA7qnwlK759V2iApCID34XjDvyqM4D1qFmoemE3qLCRZKIrrpew3PJfgLRQyy730vDymYXURKjgMmyttviH0iAMx9S6aE1dONhmYJwM6hcx5VXXUaIkWZBYVp3fP0c= 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=ZGQ0fDO+; arc=none smtp.client-ip=198.175.65.15 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="ZGQ0fDO+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1784311801; x=1815847801; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=SIkNe2VoDIMYydSotihO3ya17IET6rA23vsy2BTnTsE=; b=ZGQ0fDO+GDjwBcV0Hm+smQ3yHI+y233YPQ2asyRRmssW5Suftj4vEoo8 kqH5PDj7VLxBDHau+8K4eXcUUJTx/THstXcK9pBw3KvN2dMTU7Al4C5e3 RHwOtenRNSXPTn1jrEogKk3v6/ixaSrOD7nV29X055h1wuDr3zQ6SRPtU VLq7vdYcnhkNhI3LwGifYg8QKZEka3fBwGO1hb6Fl3y1hrSjNNANFIX8R mE2ZsV6Gy0O78mTigGT8qzzT1o0jhJ1xk4UsEGRUdgEBvem62uJCl23qb 0ZplzVnLsXrRU9bTnDOxYjmK5ofvvFXJRr8OpPw3jgRc4zs8zDI1d0Qx+ g==; X-CSE-ConnectionGUID: ImgTenESRdORk32sbSsY8Q== X-CSE-MsgGUID: z+KeioVgT1uR6tlHCP19oA== X-IronPort-AV: E=McAfee;i="6800,10657,11849"; a="88665233" X-IronPort-AV: E=Sophos;i="6.25,169,1779174000"; d="scan'208";a="88665233" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2026 11:10:02 -0700 X-CSE-ConnectionGUID: TbpizYBdSsm/W586b3aLhw== X-CSE-MsgGUID: W4P2RYFbSOm0+ZUYR9gTQQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,169,1779174000"; d="scan'208";a="258852307" Received: from pgcooper-mobl3.ger.corp.intel.com (HELO localhost) ([10.245.245.143]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2026 11:09:57 -0700 Date: Fri, 17 Jul 2026 21:09:54 +0300 From: Andy Shevchenko To: jean-baptiste.maneyrol@tdk.com 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 2/2] iio: invensense: improve period measurement by using a longer delay Message-ID: References: <20260717-iio-common-inv-sensors-timestamp-rework-v1-0-d1afee2805cd@tdk.com> <20260717-iio-common-inv-sensors-timestamp-rework-v1-2-d1afee2805cd@tdk.com> Precedence: bulk X-Mailing-List: linux-iio@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: <20260717-iio-common-inv-sensors-timestamp-rework-v1-2-d1afee2805cd@tdk.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Fri, Jul 17, 2026 at 02:39:41PM +0200, Jean-Baptiste Maneyrol via B4 Relay wrote: > Period measurement can be difficult when using high sampling > frequency where the jitter criteria is hard to meet because of the > system jitter. > > This new version is using the delta time between 2 distant interrupts > to measure an interval of at least 20ms. 20ms is a good compromise > between the mitigation of system jitter and the delay to update > period. This way we decorrelate the period measurement from the > interrupt timestamps syncing using only the 2 last interrupts. ... > void inv_sensors_timestamp_interrupt(struct inv_sensors_timestamp *ts, > size_t sample_nb, int64_t timestamp) > { > + const int64_t delta_threshold = > + INV_SENSORS_TIMESTAMP_MIN(INV_SENSORS_MIN_IT_DELTA, > + ts->chip.jitter); This is less readable than the split version. const s64 delta_threshold; Also, what const gives us here? > struct inv_sensors_timestamp_interval *it; > int64_t delta, interval; > uint32_t period; > - bool valid = false; > + bool valid; delta_threshold = INV_SENSORS_TIMESTAMP_MIN(INV_SENSORS_MIN_IT_DELTA, ts->chip.jitter); (yes, I would go for a bit longer line). > if (sample_nb == 0) > return; And why to assign it if we have to return, for example here? Move the assignment closer to its first user. -- With Best Regards, Andy Shevchenko