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 phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 77A2AC00A5A for ; Thu, 19 Jan 2023 17:22:26 +0000 (UTC) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id BDB6F8568C; Thu, 19 Jan 2023 18:22:24 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Authentication-Results: phobos.denx.de; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.b="MRJcgC5Z"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id 9E3FA85694; Thu, 19 Jan 2023 18:22:22 +0100 (CET) Received: from mail-ej1-x635.google.com (mail-ej1-x635.google.com [IPv6:2a00:1450:4864:20::635]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id E60288568B for ; Thu, 19 Jan 2023 18:22:19 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=sjg@google.com Received: by mail-ej1-x635.google.com with SMTP id v6so7507497ejg.6 for ; Thu, 19 Jan 2023 09:22:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Ga7iF43IILEzYqUH/GIcP7Xcn+eeM29w+LOPjfIvNtU=; b=MRJcgC5ZvwiW4la9QmKaM8DACsZpiB9cWuK0jDbB7nNIh0QakDfoLh+UlVKvC2MDj3 6vpwESTFs9q7h+1XaYbhjKC3L4DpHxpF8fzhSqplH7RVM9C+tPcK9bGdUToZtulaYt9x ig2GDqcYoY0H8chEMhNfiT1sh8rKhw+bYR/GU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Ga7iF43IILEzYqUH/GIcP7Xcn+eeM29w+LOPjfIvNtU=; b=0hANn3C3ftKkFBZYNBYQiChUGzIRVPOnoKi0J46Wd0lp4z2RMJ29EBRU39SzJiR1ZR TTon3gESuRHnlcoxlrNhd7w8rCExwSeCT4qllSQYUCzOxEfmA1kx6JnLLAD757kwYT6n /q9+lu9R4rePiAyhEF9IL2IzgA9R33pOI3tWfw2Qg9rxS7LrDLZOodELdwM3Bn7zsOdR ym+wn7YkCT3Y5JGtHuevDZaxfodeK3BqXIXUNQK0bN5yVz0NjApf+bB/JspuFasTgwkj EMRbsEgawdJL88z2AdnZZ3EjYvmyf7wX4yw5bmFoVIqRg5/ZaRM0dW8QDQjLwOxIdLzB oF8g== X-Gm-Message-State: AFqh2kohycDOqmbqzAZTtx588frT1d77cbSctitffJDxNXUvpN5n4eqV iwF6+CnAv5wxG3tYRVhCysSIwiQcbkaGJ2lp9x2Mkg== X-Google-Smtp-Source: AMrXdXv0I7N05sp7N0K6AnUTtUIG2tBqa6rALhldQfFVUwY9pc8oFCj0VCKaSA6mBNUubDe9aIg6/+6g2dAvdo/etEY= X-Received: by 2002:a17:907:3c07:b0:84d:1491:c038 with SMTP id gh7-20020a1709073c0700b0084d1491c038mr1549875ejc.589.1674148939123; Thu, 19 Jan 2023 09:22:19 -0800 (PST) MIME-Version: 1.0 References: <20230118124923.GB631605@bill-the-cat> <20230118135932.GC631605@bill-the-cat> <20230119163157.GA18384@e121910.cambridge.arm.com> <20230119164652.llh66rapyqqej63f@bogus> <20230119165744.GG631605@bill-the-cat> <20230119170945.cppg6irr7a26sv7n@bogus> In-Reply-To: <20230119170945.cppg6irr7a26sv7n@bogus> From: Simon Glass Date: Thu, 19 Jan 2023 10:22:07 -0700 Message-ID: Subject: Re: [PATCH v8 03/10] arm_ffa: introduce Arm FF-A low-level driver To: Sudeep Holla Cc: Tom Rini , Abdellatif El Khlifi , achin.gupta@arm.com, xueliang.zhong@arm.com, Drew.Reed@arm.com, robh@kernel.org, jens.wiklander@linaro.org, ilias.apalodimas@linaro.org, u-boot@lists.denx.de Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.39 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean Hi Sudeep, On Thu, 19 Jan 2023 at 10:09, Sudeep Holla wrote: > > On Thu, Jan 19, 2023 at 11:57:44AM -0500, Tom Rini wrote: > > > > But it's also true that at run-time, within U-Boot, we can modify the > > device tree we have, with live tree yes? So, the whole series in > > question here can be done without modifying the base DT and getting in > > to the further discussions that doing so entails. The assertion is that > > the software discoverable bus here is sufficient to not need DT, so, OK= , > > lets go. > > OK, may be I am not up-to-date on the U-Boot. IIUC, the modifications > done in the DT by U-Boot is mostly for consumption by the next stage > loader/OS and not for self-consumption. But if it is for self consumption= , > then good. It helps especially for the subnodes(as Simon referred) or the > partitions that can be discovered at run-time using FF-A interface. It's really just dodging the issue though, because you need a compatible string and you might as well add it to the DT in the source as do it at runtime. > > As mentioned I am not again DT, it is just not needed and especially > for subnodes it could result in inconsistency b/w what is in DT and > what the firmware provides. As mentioned in previous response, having a > simple node that Simon provided as example earlier is fine by me if that > is the only option to make progress as I just feel it is redundant and > one can say not scalable(but that is debatable again =F0=9F=98=84). Gosh, how many of these things are you going to add? I believe the inconsistency argument is dealt with by the bind/probe explanation. It may be redundant in Linux but I doubt it would hurt there either. > > In short, I am not concerned about having simple node, just don't like > to see entire FF-A bus enumerated in DT as subnodes for reasons mentioned > already. Fair enough, and that is agreed on my side. I'll note that with PCI we sometimes do add nodes in order to provide parameters to the driver, there being no other sensible way to do this in U-Boot, for example: https://github.com/u-boot/u-boot/blob/master/arch/x86/dts/chromebook_coral.= dts#L183 Regards, Simon