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 D2295D3F074 for ; Wed, 28 Jan 2026 14:39:09 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2800A10E70A; Wed, 28 Jan 2026 14:39:08 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="WQGNVXp4"; dkim-atps=neutral Received: from mail-pj1-f49.google.com (mail-pj1-f49.google.com [209.85.216.49]) by gabe.freedesktop.org (Postfix) with ESMTPS id 30FD210E498 for ; Mon, 26 Jan 2026 20:49:24 +0000 (UTC) Received: by mail-pj1-f49.google.com with SMTP id 98e67ed59e1d1-34c21417781so2527709a91.3 for ; Mon, 26 Jan 2026 12:49:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1769460564; x=1770065364; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=DgBDIJIrUHpJ6j6lR+sPmz5sI1yJjso51mAmb29uJAg=; b=WQGNVXp4pNUp0Zi61cSUHTymPZn5edAJK0q2CtWppbPL99TmmWOcj3+74weKjHn7PW xlkbZ3PViClUNTba7WRBr+Z+YabIaf+4E/4WN+DB2rk+93beZZH6cCLs0zzINCR0JW3Q 8rqyTymDMzhCIdHbLeze4xftKDlHUzDxyoR9VoHBEBufGqQ48/5xjvdJgKq/WzCPI3fn +rmYTpI0EC8TotjprwYZaQJNWakmSkOSrWd4eLzmKGdux6YbviM+VwuWamU85IBEyTQx MxX9HlmUXkGQgpYi+Qr6ppXer3CpTcuH41er0374XfBE0LYAUhy9B1FLAMUSO4uVYNzL yQaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769460564; x=1770065364; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=DgBDIJIrUHpJ6j6lR+sPmz5sI1yJjso51mAmb29uJAg=; b=dtaaLsbyuvXvtx59SNaN6OzaMDk95PHgbi63syELNVEDU+/1F0VabnT1YJ8FZDlvjA c/VRbZUPUitCtcgt6zGl5TLXoF0rpi5IolD2c59U3zt1isTU5X0qFaQwAS2bHVa94xu7 vcmpOyu5u9EBwhsbRN1nriE21bqYQqgWqYPALJ7+eYDLeNHZzW7CCPVyqhy/qKas7CSv pdUJ2vZHRfusH2wHpvf0/5SEisZca+/oqsBQlq//Bzz5Ob3hW6MSkd+NzzQzCpderwqU 6sV0o7Ki3Dozbep4dRt5PvNHKFibX1u+tAteIddGRlNK1DEMPc0erffpy+WCd22+K0cP bJ3Q== X-Forwarded-Encrypted: i=1; AJvYcCX0eNWRFWcAAjLGelcp9uK1EQFjx53f+A8eRSmwq9w11kDkB/cT4Mb8xqw7yKeSgtTnefZbkkH/HkQ=@lists.freedesktop.org X-Gm-Message-State: AOJu0YzYl+zFiRUOtzv7r5bnB7d1Evxz7l+7djyN7dF/8mUKcmvx2YvI BZc4DusN13gxpODOWFOC1Jso16BhJM/IwY/QCUj/0sTgKfS1cq+v5nE= X-Gm-Gg: AZuq6aJvJC4Iglxh1RzDiykyaqQhK1BYOsFV2ggUwZyQLSiGWk+FhyhuFETd2pj8p3Q dKIOuxRgFp4gHAefzmHgmY+uVX/Xy3bQXPxmOzAv/DOkSVKQGW+QPHDnOd6QSajM3qdBuJvm6JU UfAwqZv0j1w9P8klG/D1v6PXNBqNGFoVuQ78NEp9QtGTL/FHxd8eWWU0GpaSJhShA9Y4AMwTGE8 7k6Cdzh1NYqz2m8saBFA72Z22aXINTcunLBXuvX2iAn5wzsD1JgZbVmqv9domDlua3hp7GtmC3Z ZbVWy0f+ujD27QSo6YPwr8M5kwPLh6Qrd23KK5jzZt8++xiUsINOoMf6NAypS2qse9TA1jvL2jT XiRbGgEs0YvKWzrLhlwAzwsASG2kpkDX1NDgPUvwSNhygD/de7/u+f/J3j37PbCqpGgXvQt9rIv TBm5dbvDj5ZwmYdL8VA8e3SqWjMA== X-Received: by 2002:a17:90b:350e:b0:341:2b78:61b8 with SMTP id 98e67ed59e1d1-353c416b90cmr5425981a91.20.1769460563371; Mon, 26 Jan 2026 12:49:23 -0800 (PST) Received: from at.. ([171.61.166.126]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82339095c85sm5470337b3a.67.2026.01.26.12.49.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jan 2026 12:49:22 -0800 (PST) From: Atharva Tiwari To: jani.nikula@linux.intel.com Cc: airlied@gmail.com, atharvatiwarilinuxdev@gmail.com, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, joonas.lahtinen@linux.intel.com, linux-kernel@vger.kernel.org, rodrigo.vivi@intel.com, simona@ffwll.ch, tursulin@ursulin.net, ville.syrjala@linux.intel.com Subject: Re: [PATCH 2/2] drm/i915/display: Disable display for iMac's Date: Mon, 26 Jan 2026 20:49:15 +0000 Message-ID: <20260126204915.1324-1-atharvatiwarilinuxdev@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Wed, 28 Jan 2026 14:39:06 +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" > Rendering and display are quite separate in the hardware and in the > driver. Perhaps you do not mean "rendering" here? Perhaps it can be used > for rendering but not display? Yeah, it can be used for rendering but not display, sorry for the wording. > Okay, so perhaps there's no eDP connected. But what about the other > connectors on the iGPU? What about everything else in the display > hardware? You cant use the iGPU to drive the display on any hardware (including external displays). > If you can figure out that it's specifically link training that fails (a > dmesg would be useful to show this) there clearly is display hardware, > right? As said the iGPU cant drive the display on all monitors (even on macOS), but still heres the dmesg before this patch: [ 5.095489] i915 0000:00:02.0: [drm] Found cometlake (device ID 9bc8) integrated display version 9.00 stepping N/A [ 5.096061] i915 0000:00:02.0: [drm] VT-d active for gfx access [ 5.096102] i915 0000:00:02.0: [drm] Using Transparent Hugepages [ 5.099214] i915 0000:00:02.0: Invalid PCI ROM header signature: expecting 0xaa55, got 0xffff [ 5.099217] i915 0000:00:02.0: [drm] Failed to find VBIOS tables (VBT) [ 5.099324] i915 0000:00:02.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=none:owns=io+mem [ 5.100960] i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/kbl_dmc_ver1_04.bin (v1.4) [ 5.832214] i915 0000:00:02.0: [drm] [ENCODER:105:DDI A/PHY A] failed to retrieve link info, disabling eDP [ 5.835756] i915 0000:00:02.0: [drm] Registered 3 planes with drm panic [ 6.428455] i915 0000:00:02.0: [drm] Cannot find any crtc or sizes [ 6.722404] i915 0000:00:02.0: [drm] Cannot find any crtc or sizes > There's at least three levels where this could be handled, depending on > details: > > - Display probe (the patch at hand). Assumes there's no display > hardware, at all. The driver doesn't touch the hardware, which > continues to consume power, it's not put in low power states. Not > optimal if there actually is display hardware. > > - Display disable. See intel_display_device_enabled(). The driver takes > over the hardware, puts it to sleep, but prevents all connectors from > being connected. > > - eDP disable. Add a quirk somewhere to enforce eDP is disconnected, but > other connectors can be used. The main reason I sent this patch is that after i915 trys to probe the display, the dGPU (amdgpu) is no longer able to detect the internal display, resulting in a black screen. > It would be quite useful to indicate the PCI ID of the device in > question. 00:02.0 VGA compatible controller [0300]: Intel Corporation CometLake-S GT2 [UHD Graphics 630] [8086:9bc8] (rev 03) (prog-if 00 [VGA controller]) Subsystem: Apple Inc. CometLake-S GT2 [UHD Graphics 630] [106b:ffff]