From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-176.mta1.migadu.com (out-176.mta1.migadu.com [95.215.58.176]) (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 9EA6118413A for ; Sat, 27 Jul 2024 16:07:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722096478; cv=none; b=t8ZH1CO6TPISycatXB0HRIb6dV98V/4iKKpqdpzKnUpuPgKkB4eiJOUWJ8A73PnXKbL5l3tPTDjXBaaHSdGUTGkA+t0mdJeUGYPhDmbv0cvsgd22assLXHtYBnNu9hU0TdP7OFhGKjLzv8egxO4zFGF6IRyjVPb8u/1cKGgmLHA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722096478; c=relaxed/simple; bh=282oIA90G5O2Ude1KXvz8VqSWcqJ7AUYamQOvYzpDe4=; h=MIME-Version:Date:Content-Type:From:Message-ID:Subject:To:Cc; b=G5WVlNDE3bqMAGS0aI/Vy8aKhWSdwdLuIWPn8yNVt0UxmutATfKAGJjwcL7osdkGiN+IVC84EYHSQlQz7ZX725Wa4sePWirZk5MD5C/b1rPLg+6Iy3LOAqzIqba8+glgzDEsms20ulYGKtZTxVsvete3X/YqoU/oyL4QAQPtISg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=holm.dev; spf=pass smtp.mailfrom=holm.dev; dkim=pass (2048-bit key) header.d=holm.dev header.i=@holm.dev header.b=ui54UfmR; arc=none smtp.client-ip=95.215.58.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=holm.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=holm.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=holm.dev header.i=@holm.dev header.b="ui54UfmR" Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=holm.dev; s=key1; t=1722096473; 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=282oIA90G5O2Ude1KXvz8VqSWcqJ7AUYamQOvYzpDe4=; b=ui54UfmR5vMXdJJ0iaanxYyL42sTrYC6XSVVHJ+BOHc4IoY6qDcPvdwWuyi8v3Cu4TECFT zFiTN8w1SWXVDOG4mvK/AHkNxx6EPA8bbd6UERYfWBLCSg9QqHhfr+pm0nPYgNC2Rha7QN tuoCMEjPDm9W89ntjkZm81JBbEHFy4FaSNmT6rKkInQEwb/0PpDdgY1RO6+2DbFVCba53H Sen62vfu9+k6b1CsCh8STOTVkHkOAhBKJ8+XPS5sUdguqyYkY0pxEhppjw1mT/dPowy5ht 41bsTpufIfVH/++gJ1McfHuTuWLyAV8gPirJj23R0cdIQtR5PPxl53lOWq8toQ== Date: Sat, 27 Jul 2024 16:07:50 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: kevin@holm.dev Message-ID: TLS-Required: No Subject: [REGRESSION] No image on 4k display port displays connected through usb-c dock in kernel 6.10 To: stable@vger.kernel.org Cc: regressions@lists.linux.dev X-Migadu-Flow: FLOW_OUT Connecting two 4k displays with display port through a lenovo usb-c dock = (type 40AS) to a Lenovo P14s Gen 2 (type 21A0) results in no image on the= connected displays. The CPU in the Lenovo P14s is a 'AMD Ryzen 7 PRO 5850U with Radeon Graphi= cs' and it has no discrete GPU. I first noticed the issue with kernel version '6.10.0-arch1-2' provided b= y arch linux. With the previous kernel version '6.9.10.arch1-1' both conn= ected displays worked normally. I reported the issue in the arch forums a= t https://bbs.archlinux.org/viewtopic.php?id=3D297999 and was guided to d= o a bisection to find the commit that caused the problem. Through testing= I identified that the issue is not present in the latest kernel directly= compiled from the trovalds/linux git repository. With git bisect I identified 4df96ba66760345471a85ef7bb29e1cd4e956057 as = the first bad commit and fa57924c76d995e87ca3533ec60d1d5e55769a27 as the = first commit that fixed the problem again. The initial commit only still shows an image on one of the connected 4k s= creens. I have not investigated further to find out at what point both di= splays stopped showing an image. Best Regards, Kevin #regzbot introduced: 4df96ba66760345471a85ef7bb29e1cd4e956057