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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5B761CD37B9 for ; Mon, 11 May 2026 07:30:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 03BB310E4BF; Mon, 11 May 2026 07:30:28 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.b="GQQscsFi"; dkim-atps=neutral Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4881C10E04C for ; Sat, 9 May 2026 00:37:00 +0000 (UTC) Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1778287018; 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; bh=5iJBLZZZkoJSzb0I/MaSOhYRrwlcgvj54y4s369O8F4=; b=GQQscsFi/HkgF5RC/yNtWNyMcTvXK4Fx/zXg9FCKGN5TP4sKRubBbgx3N4xnsefvN1pJr2 ABP954vydhfsCWg/kHA1rcYzkcGREv9bQOqXwhUa2yTMRddf5GxLvDfg+WpyLviDr1beYQ d+w96f8zF0M2CPCOIvePXAcMPPtHVPQ= Date: Fri, 8 May 2026 17:36:53 -0700 MIME-Version: 1.0 Content-Language: en-US To: Ray Wu , Chenyu Chen , Leo Li Cc: "amd-gfx@lists.freedesktop.org" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Matthew Schwartz Subject: Regression in backlight control after 20f5481aaf17 ("drm/amd/display: Add power module on Linux") Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Mailman-Approved-At: Mon, 11 May 2026 07:30:27 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" Hello, On my Legion Go S, which has an IPS LCD screen, the brightness slider in Steam becomes very unbalanced on amd-staging-drm-next, with the bottom 45% of the slider no longer appearing to be any different than the minimum value. After bisecting, I landed on 20f5481aaf17 ("drm/amd/display: Add power module on Linux") as the first bad commit. I uploaded a dmesg from a good kernel vs a bad kernel below. Last good kernel: https://gist.github.com/matte-schwartz/e98e4d3e1d8d3c4c042e2a76450b48b1 First bad kernel: https://gist.github.com/matte-schwartz/5ef4f6967a17bc534e81f79e5cf71e02 Let me know if there are any additional details I can provide to help with debugging this further. Thanks, Matt