From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3C3A0277C9E; Wed, 12 Nov 2025 07:26:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762932397; cv=none; b=JjaGnXh4ivQ6OleH4hb1NUuuJRMOnUByd1k+WkEEKJW8WlIEltiNEsW1zwFe+jqmmRBbhgkUxhqqt+kLFHBk0TfwhvC2W5ykisXR4yc+8WxX7jH6cIbT0jE4rPsAjRL+bp8oXmEDzZXfnB75zaqWpw1U5dE6HhYUSHz4/2BCNz4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762932397; c=relaxed/simple; bh=2irZCMgg4/pD/7WqnevHbUFAeu3+60HKXvJ0LDpO2U0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Vk59BkY/2gKMYbWfBLmzVRy3FFIW4stp7Jez+NTY069vzeaUNlV2AyzUEuEXdLZIhioHcUxmUxp3ZFBpsCpdyBhQ+R+WpN1u07nROceXtZ5qN6AFuC0Tqc4fyfPB1EAYqc8g5OdN0IE0MWPR2OotUWqANwTUWib2Zl5/HxNCHk8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uo0z/N4e; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uo0z/N4e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7280C4CEF8; Wed, 12 Nov 2025 07:26:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762932396; bh=2irZCMgg4/pD/7WqnevHbUFAeu3+60HKXvJ0LDpO2U0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=uo0z/N4eheFkT7lKzplT9g5xR5nvFdn0YPAHrZJY7ad/U1Gr1esI4k1ZmDlRM2pVD aJfYHHeF2XqrFqACNwjTzMoFyvKEfcUgNbGlmvRNH6M6L9+oEqdlNVhDL8f2vK6JgM cP2mcM5iKQX2nLLYfvFSIX2RZSaPCILVJkt+fs2jhUPt9po2LNiRQhYTcjo3D9CIZo 6/MsDFbDsnCWD0ccBTXnbt+W1MMOT8MIFGvDiKzK9vAPZb6F7PYSWoUoNCdwzxHP4m THyVtXDGeUI5UcYx4AX1iYKTJ235p3bx3zXPyT1eJ2Rasr6NJ8/z9QzvOoR1ae6mc4 U7znvV5eRY8Ng== Message-ID: <6904a858-d7a3-457b-8141-692238d01582@kernel.org> Date: Wed, 12 Nov 2025 08:26:33 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 3/5] memory: tegra186-emc: Support non-bpmp icc scaling To: Jon Hunter , Aaron Kling Cc: Rob Herring , Conor Dooley , Thierry Reding , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org References: <20251027-tegra186-icc-p2-v4-0-e4e4f57e2103@gmail.com> <20251027-tegra186-icc-p2-v4-3-e4e4f57e2103@gmail.com> <82c8dda8-6fcb-48f9-bdaa-f3d1431e41ae@nvidia.com> <99ca4992-5736-417d-854e-379542549bee@kernel.org> <7f3dad08-cff5-40c2-8e7f-f6441a3d6b91@nvidia.com> <249bbe7e-e2da-4493-bdd5-8f4b17aff8fe@nvidia.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/11/2025 07:18, Jon Hunter wrote: > > On 11/11/2025 23:17, Aaron Kling wrote: > > ... > >> Alright, I think I've got the picture of what's going on now. The >> standard arm64 defconfig enables the t194 pcie driver as a module. And >> my simple busybox ramdisk that I use for mainline regression testing >> isn't loading any modules. If I set the pcie driver to built-in, I >> replicate the issue. And I don't see the issue on my normal use case, >> because I have the dt changes as well. >> >> So it appears that the pcie driver submits icc bandwidth. And without >> cpufreq submitting bandwidth as well, the emc driver gets a very low >> number and thus sets a very low emc freq. The question becomes... what >> to do about it? If the related dt changes were submitted to >> linux-next, everything should fall into place. And I'm not sure where >> this falls on the severity scale since it doesn't full out break boot >> or prevent operation. > > Where are the related DT changes? If we can get these into -next and > lined up to be merged for v6.19, then that is fine. However, we should It's still breaking all the users then. > not merge this for v6.19 without the DT changes. > > I will also talk with Thierry to see if he has any concerns about users > seeing slow performance if they don't have an up-to-date DTB. > > Is there any easy way to detect if the DTB has he necessary properties > to enable ICC scaling? > > Jon > Best regards, Krzysztof