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 3C70ACC6B1D for ; Wed, 14 Oct 2026 13:44:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B903910FE20; Wed, 14 Oct 2026 13:44:34 +0000 (UTC) X-Greylist: delayed 1164 seconds by postgrey-1.36 at gabe; Wed, 14 Oct 2026 10:14:47 UTC Received: from spark.kcore.it (spark.kcore.it [49.13.27.68]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1007110E371; Wed, 14 Oct 2026 10:14:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kcore.it; s=spark; h=References:In-Reply-To:Content-Type:MIME-Version:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date; bh=MGpHu0f14Q5TwLfq2LBRjQIPaF1PJLbbc1dVWU+dzmA=; b=iNIefWQf7xFRc0zmJwxJ8+qYN6 6CkXohhpdC+Uy5pikF7FXbT6u4Fhu6gM6rGgCPSTo3FKXh7spNzdGHp3OFGYdhiwhsjQT8P7rDLOl QgwL5wfR//J+6Ij6NTOanC2wiK5Ey6XlB0PN2Elfttar3JZP5PhM1RRC7YSje5G26b0c=; Received: from mnencia by spark.kcore.it with local (Exim 4.100.1) (envelope-from ) id 1xGvhf-00000000Jhp-0Hdn; Wed, 14 Oct 2026 11:55:19 +0200 Date: Wed, 14 Oct 2026 11:55:19 +0200 From: Marco Nenciarini To: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org, ville.syrjala@linux.intel.com, imre.deak@intel.com, jani.nikula@linux.intel.com, lyude@redhat.com, xiaolu.xie@intel.com Subject: Re: [PATCH] drm/i915/dp: clear and restore MSTM_CTRL around MST DPMS off/on Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261014081448.2320363-1-xiaolu.xie@intel.com> References: <20261014081448.2320363-1-xiaolu.xie@intel.com> X-Mailman-Approved-At: Wed, 14 Oct 2026 13:44:28 +0000 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Tested-by: Marco Nenciarini Tested on a Dell Pro Max 16 (Arrow Lake-P) with Debian 7.2.6 and a Dell WD19DC dock (Synaptics VMM5331 MST hub, fw 05.07.08) with two monitors behind it, i915 driving the dock over TBT-alt. Without the patch, a DPMS off of more than about 6 s leaves both monitors black on wake: the link status of the sink behind the hub goes from 0x77 to 0x00 and the hub does not retrain it. With the patch, 30 s, 60 s and 120 s DPMS off all kept the link and both monitors came back. The log shows MSTM_CTRL cleared before D3 and restored after D0, before POWER_UP_PHY, as intended. Details are in drm/i915/kernel#16901. -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEfCO4BD5l0pgKIbbiWJ8D8BulUDgFAmrPUYUACgkQWJ8D8Bul UDimag/+L0A6aKYws/asUDWsKnx4DjKXbQtXjYCVXx8Sqv7wG7PgYvXOONOJzvD1 dxUOxuWLDBx6sRBA6zLmtIdkkifPUHbWhADQLIOnmNqIGutzjg/Rg/TIqmtufy+w J4lxsmO6khoLa16dZZMp9p4CYgQMOd36NuWG/uSBNcNF96uxzZYjCoO5uXorCkg/ 7SCa2neKrIoXXwSEuamQC3FB83I0PXoaxP/FgzZmYDzN1IEUya4EkS78jIPCGmWC 54gz9+hNz0yRT7IgfoluNzHVnP8GftLS7t2DPH1ClZVxw6bE+UnBwpJRQ9mpCkXd DX3RCZq9E176ESqIDKI/4d+nO8AKQp06aiOExDylNU38NlSNOpPH8iN4XqwYZ2hv WlpR33hPneA1zosdZ6oFOAPNDLvF1FFuUFtA+wVLJLNNoNTRAVseHGZsR/xdL7kh X0gIyu1h2SP4wfKySiuvUmgQVm0uFphr4x+FgKn1XoZ+P0CDyjxqoFVDvE8iplb4 1IixcQAPvFasF7wq3pd2eAUh7n2zMcroi99cllGY2uPbxiOPhiWzcVV1NmQ7nHhq uFcyTlM8nV+TdZYYGCRLFkH7MHskzEGbKO+CQkYrayRPcZxZwnytnHY+CyqGr4sY 732Djo9oELBZF/fYhSBiVi7cij0NFDdadvhV1gfThIT7BH+5qhs= =2SVO -----END PGP SIGNATURE-----