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 3C345C54E49 for ; Thu, 7 Mar 2024 11:33:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E9016113052; Thu, 7 Mar 2024 11:33:33 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="UkSh176g"; dkim-atps=neutral Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by gabe.freedesktop.org (Postfix) with ESMTPS id 17F44113052 for ; Thu, 7 Mar 2024 11:33:32 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id DF95B60EB2 for ; Thu, 7 Mar 2024 11:33:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPS id 98FDDC43390 for ; Thu, 7 Mar 2024 11:33:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709811211; bh=vqJsIARby30mbF12xlo2HZYqbVA/UWzcjknJN1n/WQg=; h=From:To:Subject:Date:From; b=UkSh176gHuZ7qCJJlGz5hygxSKZKN/8hQ1vN7h6pfu8Mb7fC6ZkhRDolRsFecKeMy A8n5Lp7lw6xcPiOw7X5v6qtS1zIrt8SqUbXHcr69RLwZChTopiNroDsY/XK2Ais37V k49fIwZ8bYuY6bbfMEG3XTufxNZEJXy5oMdfju6vXWDpNzm+4/hZ0VMJoSLY3UjVRk KMn8rHfV6XOsb2fXO6U/BmUMuOI1ADqiubScnyS4AwBz3BlqCeh+FTROAJBGGU/Fpk E4uhyg5JUrgwbUxUtiV09QoGtcx2uJc97sjLaaqcnSI3BvXQVLxvG7GT+pthdYJXU+ DuF/l++ywQGnA== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 82B85C53BC6; Thu, 7 Mar 2024 11:33:31 +0000 (UTC) From: bugzilla-daemon@kernel.org To: dri-devel@lists.freedesktop.org Subject: [Bug 218569] New: Early KMS Resolution Issue on MST dock connected 4K Monitor Date: Thu, 07 Mar 2024 11:33:31 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: AssignedTo drivers_video-dri@kernel-bugs.osdl.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: Video(DRI - non Intel) X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: erenoglu@gmail.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: drivers_video-dri@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter cf_regression Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" https://bugzilla.kernel.org/show_bug.cgi?id=3D218569 Bug ID: 218569 Summary: Early KMS Resolution Issue on MST dock connected 4K Monitor Product: Drivers Version: 2.5 Hardware: All OS: Linux Status: NEW Severity: normal Priority: P3 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: erenoglu@gmail.com Regression: No My laptop, a Thinkpad P14s Gen2 AMD has two usb-c and an hdmi port. I use o= ne USB-C port to connect to Thinkpad Dock Type 40B0 which has an internal MST = hub. The Dock has 2xDP connectors and 1xHDMI. The dock is connected to a 4K TV (= LG C2), using a DP to HDMI cable. The system works fine when Wayland or Xorg starts and displays 3840x2160@60= hz. I noticed a lot of monitor sync loss when changing modes. At UEFI boot it's= at 1280x1024, then at kernel boot it switches to 1920x1080 and monitor loses signal during this transition, then SDDM or GDM starts it switches to 3840x2160, and when I login to KDE, it loses signal again for a few seconds then shows the desktop again at 3840x2160@60. So this is a nuisance for losing monitor sync but not effecting normal operation. I then tried to use the HDMI port on the laptop. I unplugged the cable from= the dock and plugged a separate HDMI cable directly to the port on the Laptop. = Then I noticed it was fully smooth. After UEFI, mode immediately switched to 3840x2160@60 with early kms and then SDDM launched without losing any signa= l. Then logging into desktop also is smooth and does not lose any signal. So I concluded something is wrong when one uses a Monitor connected to a Do= ck with MST Hub function, connected to a USB-C port on the laptop (no-Thunderbolt). Problems are: 1) When using the MST docking station, early kms does not switch to native = 4K resolution (3840x2160@60hz). I tried feeding an EDID at kernel command line= , it did not work. 2) Monitor loses signal sync when switching modes when using Dock. Does not happen when using HDMI port on laptop. This does not happen if I use a simpler usb-c hub without MST support. So a simple usb-c hub with one HDMI port out works fine. Problematic setup: Laptop --usb-c-- dock_with_mst -- dp2hdmi cable -- hdmi_port_on_4K_Monitor Working setup: Laptop -- hdmi -- hdmi_port_on_4K_Monitor Kernel Version: Linux: 6.7.8-arch1-1 bug reported to Arch as well but I'm directed to report upstream: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/issues/32 Steps to reproduce: 1) Use any recent kernel and use any docking station with an MST hub. 2) Connect a monitor to the docking station. 3) Connect Dock to the laptop using USB-C port (no thunderbolt support, ie = amd laptop) 4) Use early kms by adding amdgpu to mkinitcpio.conf modules section 5) Watch monitor resolution using Monitor functions while booting --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=