From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ECF27C433F5 for ; Mon, 28 Feb 2022 08:43:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229773AbiB1Iny (ORCPT ); Mon, 28 Feb 2022 03:43:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234062AbiB1Iny (ORCPT ); Mon, 28 Feb 2022 03:43:54 -0500 X-Greylist: delayed 122137 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 28 Feb 2022 00:43:15 PST Received: from thorn.bewilderbeest.net (thorn.bewilderbeest.net [71.19.156.171]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A75171CFEA; Mon, 28 Feb 2022 00:43:15 -0800 (PST) Received: from hatter.bewilderbeest.net (174-21-187-98.tukw.qwest.net [174.21.187.98]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: zev) by thorn.bewilderbeest.net (Postfix) with ESMTPSA id 0371C586; Mon, 28 Feb 2022 00:43:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bewilderbeest.net; s=thorn; t=1646037795; bh=/gKdAnnuZbroYlaQ/1maEmfHfcReg/Jk+7dXNcIY3XI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mAywKeEgWYu0uwHi0cjc4DPmv+LNIbBCkFIJy0jsetIuZI9D801pbW0qZqvbbILcD zMsIoevXT8Rma8I32SE9WoRTrThcUOLqzHrBe+0pMf2RXiOWVlcwuWRO+8U1QFQNi3 dWebxy0mruYhg4W2qoCUpDnzg9NvOXW20mpF8AJY= Date: Mon, 28 Feb 2022 00:43:13 -0800 From: Zev Weiss To: linux-i2c@vger.kernel.org, Guenter Roeck , Peter Rosin , Rob Herring Cc: openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v2 0/2] ic2: mux: pca9541: add delayed-release support Message-ID: References: <20220201001810.19516-1-zev@bewilderbeest.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20220201001810.19516-1-zev@bewilderbeest.net> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Mon, Jan 31, 2022 at 04:18:08PM PST, Zev Weiss wrote: >Hello, > >This series adds support for a new pca9541 device-tree property >("release-delay-us"), which delays releasing ownership of the bus >after a transaction for a configurable duration, anticipating that >another transaction may follow shortly. By avoiding a >release/reacquisition between transactions, this can provide a >substantial performance improvement for back-to-back operations -- on >a Delta AHE-50DC (ASPEED AST1250) system running OpenBMC with dozens >of LM25066 PMICs on PCA9541-arbitrated busses, a setting of 10000 (10 >ms) reduces the median latency the psusensor daemon's hwmon sysfs file >reads from 2.28 ms to 0.99 ms (a 57% improvement). > Ping...Guenter, any thoughts on this? Thanks, Zev