From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 6349C3783D8; Thu, 22 Jan 2026 16:04:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769097889; cv=none; b=CnClefzQ1Q2B7ewPEXJk1hEbjHtE8bSepD4mUpcMruLrOLC+spSUpjlkHbCk2LgFjwnHZieVlWTtV94Lf8jbPmlB7APrm28Pt5hW+DTo8dMc6kT2VP6OjsBcc+0U/OBuRtQpjothEOEHY22G1BCe948g1xasspVMH5sCh0b7dAI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769097889; c=relaxed/simple; bh=4EBQIdGZsDGt5LpjHJ0hgvsGwK+wpd4MDJekE2tbQec=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SB5z7aghlOArFIxSIgbq8BedpdGdUmniQ7eDHTJUKd7w4NbBTJe9UKNntYU7uyRMhrryP8gSipjbk4gR9ruHBwd1kjrMek+lqaPeIZzhRXHRkDK1P9nhKedK6F3H4X20bgpOQSaDnWRWS+AVdE7SiNvLtSNnsq3fbBtjU+fldI8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=J2e52Lwy; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="J2e52Lwy" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Transfer-Encoding:Content-Disposition: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:From: Sender:Reply-To:Subject:Date:Message-ID:To:Cc:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Content-Disposition: In-Reply-To:References; bh=yF87tQDfmCy5Tvh/RPnBLWnSAMsaiL33neMbXbvwmxA=; b=J2 e52LwywCUdXeS0lnw9oHIvFuyCuVsT8F9q1HiTAGC0Ymx8vaeOqZwW89iWSLQPTjl5VyA1kMvh96N AjJb8yOCBSpu6b0sDaG44gVbhXh0IfGXFK7Z8rf41k4FXIcm32YuhfZc5dfc2qvC07SO9auNDFx2H VuWOm5nqfB2jj1g=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1vixAb-003zkx-SI; Thu, 22 Jan 2026 17:04:29 +0100 Date: Thu, 22 Jan 2026 17:04:29 +0100 From: Andrew Lunn To: Jonas Jelonek Cc: Maxime Chevallier , Russell King , Heiner Kallweit , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, =?iso-8859-1?Q?Bj=F8rn?= Mork Subject: Re: [PATCH net-next v5] net: sfp: extend SMBus support Message-ID: <92538fd0-aa1f-429b-9984-89bcd46e2a28@lunn.ch> References: <20260116113105.244592-1-jelonek.jonas@gmail.com> <6a87648c-a1e8-49a2-a201-91108669ab44@bootlin.com> <6987689b-35ac-4c15-addb-1c8e54144fa7@gmail.com> <5e7c71f6-80dd-408b-a346-888e6febf07a@lunn.ch> <91442f3f-0da9-4c52-89ce-2ca0a3188836@gmail.com> <66e8424c-86c9-4ad7-a3a7-3c277bfa5432@lunn.ch> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Jan 22, 2026 at 11:14:03AM +0100, Jonas Jelonek wrote: > Hi Andrew, > > On 18.01.26 16:39, Andrew Lunn wrote: > > On Sun, Jan 18, 2026 at 10:43:12AM +0100, Jonas Jelonek wrote: > >> Hi, > >> > >> On 16.01.26 15:25, Andrew Lunn wrote: > >>>> But let's first figure-out if word-only smbus are really a thing > >>> Some grep foo on /drivers/i2c/busses might answer that. > >> Did that and haven't found any driver in mainline which is word-only. > >> All drivers with word access capability have byte access too. > > So for the moment, maybe add a WARN_ON() for an I2C bus that only > > supports word access, and we can deal with it only if we ever get a > > report of it firing. > > Should it just have a WARN_ON and continue (so it may work in some cases) > or fail at that point?  I guess doing a word access when a byte access is wanted will either work, or immediately kill the I2C bus because the SFP is broken and only supports byte access, and the dead I2C bus will cause a cascade of errors. So continue seems reasonable and hope for the best. Andrew