From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794049765; b=slb98DYFJc7KTF2DtGauE/Kw2bFpYb8hQRjoFparaRDgbBGjCzZIwHQZdJ37OWqVbrvR RwYrVidQIGhC427BZdsSdiwFJV+Yg4sgZ+8jk3wtggl6p0730nv6EQxuSdbhTjdz2/9Lm FnDGvDdAj+TMDnSGGXXypi5NECYn9AxxBJBpIgzRAUi0fn+0iTHDMeNr/BCA/rsXdlvd2 M8FKfsfvByTZHthUSIpHuiK9/BCZz3rN4Ecvo8601bvN19irtzbPX+owXKZXOGRHWPxsH 286IAUQcgFqRByzxsEgSg07VA4NfUzo5pcMP70ULB2GyMzI/9trg3AMxX2ualz1GbZg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794049765; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=bz10sdFVKlKcsV36HMhh3f6Q1B01ResZK6bpYt40Qfc=; b=RBgf2Hci28NW8kwEnMQfM9p/Ms3mWhimEFBp43ln7wVt9j3LHyE+m3WxM+w8GD8WxGuX DuFtTVqnGJrexrHmk1YFediNbLKk+20BdtsOexh/zBoA1tXJXNmsIxnGtGcO1Xl/mGgjQ vhlICaRnIIKGwgNG1RVSlXLhVVIJ9kFCzcRZDjLVVUzzhmWsOJmdieNb41/5rDtl2xQkd P/9hoTuUhiQEx5WmxfdbPu8hw60mFz5n37kMadcOB/BW83XY4jyoQsYf5V5oa1Jb9idup nrLNpdFNO0quk0QalHAQLXomcV5xvf5Smk7Lccgku+FuSZGn2pJrhZcVKCUZ0JfBVHA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MCqY3rIT; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D22A2606A326 for ; Sat, 7 Nov 2026 11:09:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MCqY3rIT Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CA081F008A1; Sat, 7 Nov 2026 11:09:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794049764; bh=bz10sdFVKlKcsV36HMhh3f6Q1B01ResZK6bpYt40Qfc=; h=From:To:Cc:Subject:Date; b=MCqY3rIT3OtP1igdiVJOiYOznrgx/hJt2DKg0any+r9N/y1lgBgOX1f6TpGHaFoSw hndVvP3ScvWsjWLnfTiZhSZx1vz+e3IQIFR7pLmO7Q31ZmbIrrDlGQ+/OmyGfSsDLz LFio6s0W/fqrrqFg5wmyA0/IdqoySfa3zgVQLjmotQq3FqCf0sqiWKTdDqV4HdRJWq iQ91nUxdYZWbG+N80u6RePUU+YgyGnbjk0Fz5I+awZWTO+2hjRvJLszK+TrHsnBXve 5bmetVYhDBm326po50sBOg924rq7LEDoePAK+gQSka/po8hvZ45WJaOOXtOJ3dlXuC 9abx1xFiK3v/A== From: Sasha Levin To: qchcio@gmail.com, alexander.deucher@amd.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0" failed to apply to 5.15-stable tree Date: Sat, 7 Nov 2026 06:09:22 -0500 Message-ID: <20261107060922-failed-5.15-5b56ede88031@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 5b56ede880317bd912f914d5cd38ba1d357677fa # git commit -s git send-email --to '' --in-reply-to '20261107060922-failed-5.15-5b56ede88031@kernel.org' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 5b56ede880317bd912f914d5cd38ba1d357677fa Mon Sep 17 00:00:00 2001 From: Maciej Kucharek Date: Thu, 15 Oct 2026 11:57:11 +0200 Subject: [PATCH] drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0 On MacBookPros with switchable graphics, the firmware puts VRAM at MC address 0 when the iGPU is enabled. The EFI stub enables the iGPU on these machines through apple_set_os(). On a MacBookPro11,5 (Radeon R9 M370X, 1002:6821, subsystem 106b:0149), the driver adopts this layout at init: MC_VM_FB_LOCATION=0x007f0000, HDP_NONSURFACE_BASE=0 VRAM at 0x0-0x7fffffff, GART table at 0x1400000 The driver posts the ASIC again on S3 resume and after a GPU reset. The VBIOS asic_init table then moves VRAM back to the VBIOS default: MC_VM_FB_LOCATION=0xf47ff400, HDP_NONSURFACE_BASE=0xf4000000 gmc_v6_0 does not reprogram these registers. The GART table is then no longer in VRAM, and the gfx ring test times out: amdgpu: ring gfx test failed (-110) amdgpu: resume of IP block failed -110 Reset and post the ASIC at driver load on Apple boards with VRAM at 0. The driver then uses the VBIOS layout (VRAM at 0xf400000000) from the start, and later posts keep it. After the reset, FB_BASE is not 0, so a module reload does not reset the ASIC again. The test is the same one that commit c54e4d105077 ("drm/amdgpu: make Mac FB workaround generic") uses: an Apple subsystem vendor and VRAM at 0. The VI quirk for the MacBookPro14,3 resets at load for the same reason: commit b6b1d9721851 ("drm/amdgpu: reset VI ASIC on MacBookPro14,3") Other Apple SI boards get the same reset if FB_BASE reads 0 at load. Tested on a MacBookPro11,5 with 7.2.5 and this patch: the panel comes up at boot, and 4 of 4 deep S3 cycles resume. Without the patch, S3 resume fails every time. The GPU reset path is not tested. Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/5978 Assisted-by: Claude:claude-opus-5-5 Reviewed-by: Alex Deucher Signed-off-by: Maciej Kucharek Signed-off-by: Alex Deucher (cherry picked from commit 60dd16ae10f286cb9cce5b6027b2d5ee869637af) Cc: stable@vger.kernel.org --- drivers/gpu/drm/amd/amdgpu/si.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/si.c b/drivers/gpu/drm/amd/amdgpu/si.c index 0adfd4b101aaf..e5e590425f42e 100644 --- a/drivers/gpu/drm/amd/amdgpu/si.c +++ b/drivers/gpu/drm/amd/amdgpu/si.c @@ -1512,6 +1512,16 @@ static void si_invalidate_hdp(struct amdgpu_device *adev, static bool si_need_reset_on_init(struct amdgpu_device *adev) { + /* + * MacBookPros with switchable graphics put VRAM at 0 when the iGPU + * is enabled. Any later post (S3 resume, GPU reset) moves it back to + * the vbios default, so reset and post on load to start with the + * vbios layout. + */ + if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE && + !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK)) + return true; + return false; } -- 2.53.0