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 C28FDC43334 for ; Tue, 28 Jun 2022 21:07:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231609AbiF1VHm (ORCPT ); Tue, 28 Jun 2022 17:07:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52832 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231518AbiF1VHk (ORCPT ); Tue, 28 Jun 2022 17:07:40 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E78303A1A1; Tue, 28 Jun 2022 14:07:38 -0700 (PDT) Received: from ssl.serverraum.org (web.serverraum.org [172.16.0.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 8575822246; Tue, 28 Jun 2022 23:07:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1656450456; 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=bcnmTdzKIt3h8Y/cXjAdBaWMZpAGYim0e79RrQFMrHc=; b=BxoSIxSld2y217J+0raDd+5Og1lRRU6snjcxB8pR7pJ9N56FXcy/LdBf0iJJjzT0+ozZTd LsUaTNCqrOKVhp8xuIAdQFzQNEVE267QifIa7wW8it7dTsS3Rf2K4acGMboA46D06bCmPB etoEeefURRQ2b/1U7cqikoNYBa7mQdY= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 28 Jun 2022 23:07:34 +0200 From: Michael Walle To: Horatiu Vultur Cc: Andy Shevchenko , Krzysztof Kozlowski , Andy Shevchenko , "Rafael J. Wysocki" , Rob Herring , Krzysztof Kozlowski , ACPI Devel Maling List , devicetree , Linux Kernel Mailing List Subject: Re: fwnode_for_each_child_node() and OF backend discrepancy In-Reply-To: <20220628205254.gnllvaz7w5jmpfe5@soft-dev3-1.localhost> References: <2f2d7685e0e43194270a310034004970@walle.cc> <9e58f421c27121977d11381530757a6e@walle.cc> <3ab8afab-b6b7-46aa-06d4-6740cee422d7@linaro.org> <288f56ba9cfad46354203b7698babe91@walle.cc> <96f40ae6abf76af3b643b1e1c60d1d9f@walle.cc> <20220628205254.gnllvaz7w5jmpfe5@soft-dev3-1.localhost> User-Agent: Roundcube Webmail/1.4.13 Message-ID: <4782de1fc6692a98bd6c267c2714325f@walle.cc> X-Sender: michael@walle.cc Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 2022-06-28 22:52, schrieb Horatiu Vultur: > The 06/28/2022 22:28, Andy Shevchenko wrote: >> EXTERNAL EMAIL: Do not click links or open attachments unless you know >> the content is safe >> >> On Tue, Jun 28, 2022 at 5:17 PM Krzysztof Kozlowski >> wrote: >> > On 28/06/2022 17:09, Michael Walle wrote: > > Hi, > > Sorry for joint this late. > >> >> ... >> >> > > Mh. Assume a SoC with an integrated ethernet switch. Some ports >> > > are externally connected, some don't. I'd think they should be disabled, >> > > no? Until now, all bindings I know, treat them as disabled. But OTOH >> > > you still need to do some configurations on them, like disable port >> > > forwarding, disable them or whatever. So the hardware is present, but >> > > it is not connected to anything. >> > >> > I see your point and the meaning is okay... except that drivers don't >> > touch disabled nodes. If a device (with some address space) is disabled, >> > you do not write there "please be power off". Here the case is a bit >> > different, because I think ports do not have their own address space. >> > Yet it contradicts the logic - something is disabled in DT and you >> > expect to perform actual operations on it. >> >> You beat me up to this comment, I also see a contradiction of what >> "disabled" means in your, Michael, case and what it should be. >> >> If you need to perform an operation on some piece of HW, it has not to >> be disabled. >> >> Or, you may deduce them by knowing how many ports in hardware (this is >> usually done not by counting the nodes, but by a property) and do >> whatever you want on ones, you have not listed (by port_num) in the >> array of parsed children. > > It is not possible to have a defined for the MAX number of ports that > supported by lan966x. Which is 8. And assigned that define to > num_phys_ports instead of counting the entries in DT? You mean also for the lan9662? I'm pretty sure that doesn't work. Have a look where num_phys_ports is used. One random example: https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/microchip/lan966x/lan966x_main.c#L874 So if your switch only has 4 ports, then I'd guess you'll access a non-existing register. -michael