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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 967D7C433DB for ; Tue, 5 Jan 2021 08:11:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4CE3422257 for ; Tue, 5 Jan 2021 08:11:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727186AbhAEILF convert rfc822-to-8bit (ORCPT ); Tue, 5 Jan 2021 03:11:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:39686 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727129AbhAEILF (ORCPT ); Tue, 5 Jan 2021 03:11:05 -0500 Received: by mail.kernel.org (Postfix) with ESMTPS id B26F722257 for ; Tue, 5 Jan 2021 08:10:24 +0000 (UTC) From: bugzilla-daemon@bugzilla.kernel.org To: linux-pm@vger.kernel.org Subject: [Bug 210993] Intel frequency scaling causes electrical noise on 10th gen CPUs Date: Tue, 05 Jan 2021 08:10:24 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Power Management X-Bugzilla-Component: cpufreq X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: enhancement X-Bugzilla-Who: karolherbst@gmail.com X-Bugzilla-Status: NEEDINFO X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: linux-pm@vger.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=210993 --- Comment #10 from Karol Herbst (karolherbst@gmail.com) --- (In reply to Francisco Jerez from comment #7) > (In reply to Karol Herbst from comment #6) > > > > > Does disabling some specific idle state (e.g via > > > /sys/devices/system/cpu/cpu*/cpuidle/state*/disable) have any effect on > the > > > noise? > > > > disabling all except state0 stops the noise. > > Ah that makes sense, that sounds like the culprit might be a noisy power > supply coupled to the oscillation of the processor's current draw caused by > repeated C-state transitions. If that's the case you may be able to tweak > the latency parameters to make sure the oscillation frequency is outside the > audible range, though I'm not sure if it would make sense to upstream such a > change since it will likely come at an energy cost (Though I would expect > the cost to be minor as long as the processor can still reach the deepest > sleep state in the steady state while idle, might be a good trade-off in > your specific case if this is particularly annoying to you). yeah... might be. Although it felt like this is a more common issue with newer CPUs, especially 10th gen Intel CPUs and was wondering if there is a way to mitigate it in software. Limiting the max clock helped to reduce it, so I was wondering if there could be some nice ideas for people too lazy or not wanting to bother with replacing the laptop or whatever. -- You may reply to this email to add a comment. You are receiving this mail because: You are the assignee for the bug.