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 4D9DD190485; Mon, 7 Apr 2025 20:39:21 +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=1744058363; cv=none; b=VY8Z5Kj4wjXG9zo5is6AviU8M7pxuqY4dMtyqheANDAZfUyDGdMqYc6k9HZSBHR8M4TIph8P1RDB7QWNaic7ZcLIB18xZa1fQE3CTJpbA5JtDrmnGoz/SoMJOUZ5KVhQRgOAOLVgMmxVkSM3uFM3KvhoKjaFsa8oOD0/K9wBqOY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744058363; c=relaxed/simple; bh=V7DUCjs9kVxBcWLtbI3zoQPAQpX2qv+UjffXf4Yk/Wo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HpeJSq1lP6NKfNygCZxHYeh7F7/p0mz4aN0IYcYQ2dNxrK4+BRE4PBZjxY9wD8ku7FKqgDIedlqoH2BCvVFzprOEV8npx9s/l1xgd0oH01IXgmASky3zRLCyugrIKBMcl8Hty9WP12BXzWoyiaz8ZwWDxZF0tpP48cF3RQCzf2A= 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=csqrYtYL; 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="csqrYtYL" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To: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=tQe0PGDZfmp8rpY/ZTodvp4bt57E+3mmu/u8JN+CI9E=; b=csqrYtYLrstOUDID8fDr0c9AqB F0CAlOxBHi8sEuYWLH4NxtpkFB0cFnr/nEQ9zSvw1CMeufnlKnqafFISAsHlRWfJYS3qx6ykJO0gz 5lcu6+wGw3Hukod7vFax88KwlV/trkypwiQU7uuG2TcYyE51USeDS5vIaTwlML5OslVw=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1u1tFV-008IsL-2W; Mon, 07 Apr 2025 22:39:17 +0200 Date: Mon, 7 Apr 2025 22:39:17 +0200 From: Andrew Lunn To: Marek Pazdan Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.org, Tony Nguyen , Przemek Kitszel , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Kory Maincent , Willem de Bruijn , Alexander Lobakin , Mina Almasry , Edward Cree , Daniel Zahka , Jianbo Liu , Gal Pressman Subject: Re: [PATCH 1/2] ethtool: transceiver reset and presence pin control Message-ID: <8b8dca4d-bdf3-49e4-b081-5f51e26269bb@lunn.ch> References: <20250407123714.21646-1-mpazdan@arista.com> 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=us-ascii Content-Disposition: inline In-Reply-To: <20250407123714.21646-1-mpazdan@arista.com> On Mon, Apr 07, 2025 at 12:35:37PM +0000, Marek Pazdan wrote: > Signal Definition section (Other signals) of SFF-8636 Spec mentions that > additional signals like reset and module present may be implemented for > a specific hardware. There is currently no user space API for control of > those signals so user space management applications have no chance to > perform some diagnostic or configuration operations. How do you tell the kernel to stop managing the SFP? If you hit the module with a reset from user space, the kernel is going to get confused. And how are you talking to the module? Are you going to hijack the i2c device via i2-dev? Again, you need to stop the kernel from using the device. Before you go any further, i think you need to zoom out and tell us the big picture.... Andrew