From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mslow1.mail.gandi.net (mslow1.mail.gandi.net [217.70.178.240]) (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 9816112E65 for ; Fri, 20 Oct 2023 13:57:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="biU7ESoH" Received: from relay2-d.mail.gandi.net (unknown [217.70.183.194]) by mslow1.mail.gandi.net (Postfix) with ESMTP id BF717CF3FA for ; Fri, 20 Oct 2023 13:45:39 +0000 (UTC) Received: by mail.gandi.net (Postfix) with ESMTPSA id C67564000F; Fri, 20 Oct 2023 13:45:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1697809531; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lr/z7uihQprUld3MCX8m2TxbGzxLF1jBcFQtsJ1q8Lc=; b=biU7ESoHpgUw+DDQz7V86GfiGC9KtHEliOGtPOBH2lqU8v9/dKa7TpQRy/qtWhw8nFH2iv SPRudRRN8PXjnJSt1sep9Vyoc2uvua23p4NRnADvgbOFKXF9mYrqgSa2XYkuvqGRMkXqih 2Djs7z08wehMsdbDIskMWYzd2tv3SX+rYNAMX16zDcP03I1XMldDNv98b8aUIcFRx3QMyx L58Kusya/Twsickg6kRU0wnTpc5bksBZaWwlRxkmITvRWxHFGXzc/hIhcgXO5l8bd5FHp4 9vTzCJC9Nr0T8VqOiewC15HTEuoOlfOBaNkbhdeIfHIBRzw7WnBR4SGJnvgOnQ== Date: Fri, 20 Oct 2023 15:45:28 +0200 From: Miquel Raynal To: "Zbigniew, Lukwinski" Cc: Frank Li , alexandre.belloni@bootlin.com, conor.culhane@silvaco.com, imx@lists.linux.dev, joe@perches.com, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/6] i3c: master: add enable(disable) hot join in sys entry Message-ID: <20231020154528.2f5f68f5@xps-13> In-Reply-To: <57efe6de-cf65-32ed-fd1e-a388e1676c70@linux.intel.com> References: <20231018205929.3435110-1-Frank.Li@nxp.com> <20231018205929.3435110-2-Frank.Li@nxp.com> <57efe6de-cf65-32ed-fd1e-a388e1676c70@linux.intel.com> Organization: Bootlin X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: imx@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-GND-Sasl: miquel.raynal@bootlin.com Hi Lukwinski, zbigniew.lukwinski@linux.intel.com wrote on Fri, 20 Oct 2023 10:55:27 +0200: > On 10/18/2023 10:59 PM, Frank Li wrote: > > Add hotjoin entry in sys file system allow user enable/disable hotjoin > > feature. > > > > Add (*enable(disable)_hotjoin)() to i3c_master_controller_ops. > > Add api i3c_master_enable(disable)_hotjoin(); =20 >=20 > What is the use case for having HJ enable knob in sysfs available for use= r space other than for debug stuff? In other words, does user space really = need to enable/disable HJ in runtime for other reason but debug? If it is o= nly for debug maybe it=C2=A0 could be move to debugFS? I don't think hotjoin should be considered as a debug feature. The problem here is the power consumption which is higher if you enable this feature (you need to keep everything clocked and ready to handle an IBI) whereas if your design is "fixed" (more like an I2C bus) you may save power by disabling this feature. A module parameter does not fit here because it's a per-bus configuration. Thanks, Miqu=C3=A8l 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 63512C0032E for ; Fri, 20 Oct 2023 13:46:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=mt9y44BtZmchNf/Z4DVA2AvhD+G4tYHhDig92iuet1I=; b=Hr7BwVESGHI4nj Ng0KYnKSykmyhwz7T3zCDEZsoHv2HSztzkUfAMMy8rZFz1aAU3NNrIG4UffRJfENyVeRG4EVxkS3p tXFHeHp9ylopOEK5Ej3AsQOtv+XquTzzOxybC6Nf4t74SlJLzFXXF1qmVFEw71gSlYhAdp7gz0R0A M88tY0mQLbb5lQ0XIu+uCTAX/xFGd0BvNJqkcUeMRGiRIzNsjGOV1eqGzauW6ZfONG+mie1nkBi8Q dWtQQhZvnsOUMlFD7Ky1HP5xxC1z/mLRjMz3kV2pOmCOTYjEpE3e0oMH8MvaTiu4Ptl4YCGM0hPz4 eavurayyFy1FrtOTI2sg==; 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