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 9A9C5C56201 for ; Fri, 20 Feb 2026 13:43:59 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0AD4C10E7DD; Fri, 20 Feb 2026 13:43:59 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="r5Styz2j"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id B05E910E5FB; Wed, 18 Feb 2026 16:24:08 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id CD007600AE; Wed, 18 Feb 2026 16:24:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB259C116D0; Wed, 18 Feb 2026 16:24:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771431847; bh=XYx/puUdchWDytGa+LGQR4+MU2KhVE1/fmjSkr5+LWg=; h=From:Date:Subject:To:Cc:From; b=r5Styz2jYvKkoCBZmsXD9suT5i+Gbny5BIzhmXAukoHUgIqs6TjCj0E6ylTFXF/no oo9xRz9+IlyFjIiYdp9C8uOsbNjK5Fs5GdT26tKbe+9CnFdIAU8p+32ZBmpD4xmdbU v7QXjXFxa9QLFaJNJa7gPz0mZ1wPQbO9GoD6U0fCyiiSUf+u5WAZULaAiZdcNOnZcQ i78Dm/qX0c4oHmcYQeuNcAlsow1E1cBr0hzesEDxcSn2J52gi2km/vj9PhnilsrQP5 NRgiO/Mj+w+ZVMEQQ08rlWtwtnmj3dxgOxGhf3gGCoUHhQyJ9M1qb2REOXOlpckaBt AxWvPxBPK5PTw== From: Benjamin Tissoires Date: Wed, 18 Feb 2026 17:23:54 +0100 Subject: [PATCH] drm/i915/vrr: partial revert of dda7dcd9da73c5327aef42b89f0519bb51e84217 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260218-wip-fix-iris-plus-v1-1-e6b969defd6d@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/x2MSQqAMAwAv1JyNmBzKOpXxEO1UQNSS4MLiH+3e ByYmQeUs7BCZx7IfIrKHgvYysC0+rgwSigMVJOryTZ4ScJZbpQsimk7FKnxrXVEdgwTlC5lLsL /7If3/QCO9hrWYwAAAA== X-Change-ID: 20260218-wip-fix-iris-plus-28a916221bdc To: Ankit Nautiyal , Jani Nikula , Rodrigo Vivi , Joonas Lahtinen , Tvrtko Ursulin , David Airlie , Simona Vetter Cc: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Benjamin Tissoires X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1771431844; l=3692; i=bentiss@kernel.org; s=20230215; h=from:subject:message-id; bh=XYx/puUdchWDytGa+LGQR4+MU2KhVE1/fmjSkr5+LWg=; b=C3AE7r2rmWJX9BG6OwvzUqhtho3E17pQDfw6nXfcLDdxG182+RIJpSv81Rwpfx58+eX9I0rTi 4Rky16tOtxBD+ApTrkpPWg+4fJ41ZuYd57V6PgR3XlfTIymLFO3dIof X-Developer-Key: i=bentiss@kernel.org; a=ed25519; pk=7D1DyAVh6ajCkuUTudt/chMuXWIJHlv2qCsRkIizvFw= X-Mailman-Approved-At: Fri, 20 Feb 2026 13:43:49 +0000 X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Commit dda7dcd9da73 ("drm/i915/vrr: Use fixed timings for platforms that support VRR") introduced a regression on my Ice Lake laptop with an Iris Plus G7. The screen can go blank (screen lock or just idle), but if I try to wake it up, there is an immediate kernel lock. The netconsole was really unhelpful here, and a bisect gave me the commit above to be the culprit. For reference, the netconsole I could get was: [ 103.553110] netconsole: network logging started [ 125.642395] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 6: ba00000011000402 [ 125.642400] mce: [Hardware Error]: RIP !INEXACT! 33:<00007fa4471665ec> [ 125.642403] mce: [Hardware Error]: TSC 38282e339d [ 125.642404] mce: [Hardware Error]: PROCESSOR 0:706e5 TIME 1771365482 SOCKET 0 APIC 0 microcode ca [ 125.642406] mce: [Hardware Error]: Run the above through 'mcelog --ascii' [ 125.642406] mce: [Hardware Error]: Machine check: Processor context corrupt [ 125.642407] Kernel panic - not syncing: Fatal machine check [ 125.642415] Kernel Offset: 0x1d400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) and then the backtrace lead to the netconsole in itself. If I restore the early return when vmin >= vmax (in my case vmin==vmax), then I can use my machine again after it goes idle. I have strictly no ideas if this is the correct solution, so please take this with a grain of salt, but this is effectively preventing me to use distro kernel since v6.16. Signed-off-by: Benjamin Tissoires --- I've been experiencing this bug since kernel v6.16. System Information Manufacturer: Dell Inc. Product Name: XPS 13 7390 2-in-1 cpu: Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz lspci: 00:00.0 Host bridge [0600]: Intel Corporation Ice Lake-LP Processor Host Bridge/DRAM Registers [8086:8a12] (rev 03) Subsystem: Dell Device [1028:08b0] Flags: bus master, fast devsel, latency 0, IOMMU group 2 Capabilities: Kernel driver in use: icl_uncore 00:02.0 VGA compatible controller [0300]: Intel Corporation Iris Plus Graphics G7 [8086:8a52] (rev 07) (prog-if 00 [VGA controller]) DeviceName: To Be Filled by O.E.M. Subsystem: Dell Device [1028:08b0] Flags: bus master, fast devsel, latency 0, IRQ 188, IOMMU group 1 Memory at 603d000000 (64-bit, non-prefetchable) [size=16M] Memory at 4000000000 (64-bit, prefetchable) [size=256M] I/O ports at 4000 [size=64] Expansion ROM at 000c0000 [virtual] [disabled] [size=128K] Capabilities: Kernel driver in use: i915 Kernel modules: i915 Again, I have really no idea if this is the correct fix, but it would be nice if the issue could be solved in v7.0 and backported to older kernels. Please tell me if I need to provide more information. Cheers, Benjamin --- drivers/gpu/drm/i915/display/intel_vrr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c index b92c42fde937..3d16dd4611d9 100644 --- a/drivers/gpu/drm/i915/display/intel_vrr.c +++ b/drivers/gpu/drm/i915/display/intel_vrr.c @@ -377,6 +377,9 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state, vmax = vmin; } + if (vmin >= vmax) + return; + if (crtc_state->uapi.vrr_enabled && vmin < vmax) intel_vrr_compute_vrr_timings(crtc_state, vmin, vmax); else if (is_cmrr_frac_required(crtc_state) && is_edp) --- base-commit: 05f7e89ab9731565d8a62e3b5d1ec206485eeb0b change-id: 20260218-wip-fix-iris-plus-28a916221bdc Best regards, -- Benjamin Tissoires