From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.95 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793802028; b=Hopce10hrArfLsQFczCm7btjANbMnmjeZ+kmR64H8aDbGvq5qvgLg8O2zKdIWehxutl3 Wm/23sSZ1IJUk8AEzXMJbeTqXEVEOG8jGETJSnxWvL6HfEXO/8WVLdjlQ6CYetd0ZmjUc Ub3P08sz6HnZ6WMLRzcflSjdbb+VCUj3nhV6fWyLumiu7C5F0IN6N9/ZAzmC70HjbGcA4 FvIvEXK/b/sAx/1DT68hZ5woeg9zAzniKipcn4jJDM2UbQbgxUUJx3MqgSejad51WQExd LA18MsIc9ngjYJt0kvJUEuwTm84VevgmyiCQ1CnSLx3aQFnVESa29v4bc/xWt471Gew== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793802028; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Content-Transfer-Encoding: From:Mime-Version:Subject:Date:Message-Id:References:Cc:In-Reply-To: To:X-Mailer; bh=m/NZtHpS1SjJGqrEJRDxwvaLB3PXvzyilEksZKPIUz0=; b=KQySlABgI1nMBVMg3O5puqVWYYMmpauXH+2Zm3luCrR9H3zu7nxI26dL8ZnKKG6CNq3l ekdBbWZCdZNhAXhKV6M+vWW5ps8iYsHi5J62Jtsz7M08Fnm8Zr/v3By9xpMEJf5YPi5pI UAH19J0cScT2YNYS7xjtQczjqDpADEcwW2VngyfZbt9UcA2rmIJ8tmqEf3P8ZjyMzg5Hy 4gDK0ZEVwunSKjfrd0s8vU0fbhzc8XN6R9KQyprxECr+kKip+rUvffjFRzT5Rd5P4bJly xT7kF4vcoeLil6I3cwjNCm1pfZR/LkEHvP4lB3Z8bEaGEiClPBci2Eq+XgTaUrwjzBA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=jGv9fWpQ; arc=none smtp.remote-ip=95.215.58.95 Received: from mta1.migadu.com (out-95.mta1.migadu.com [95.215.58.95]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 24D3D606A329 for ; Wed, 4 Nov 2026 14:20:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 24D3D606A329 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=jGv9fWpQ X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=m/NZtHpS1SjJGqrEJRDxwvaLB3PXvzyilEksZKPIUz0=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793802025; v=1; x=1794406825; b=jGv9fWpQmTdYWYoxQBN7ogkIaGZJPDvSguBCljUwRGytolBnLPSp3IxKlrqeQCk4MkCu+niW 5B3o+LgPTiPxBk4q/HoZkU6fIvC+9bdK/tLJimgG853R2fenIA9gEnD7wlJoB2IrZF3tyOxY4NW qKKSh7G6qnfAatipvVihy7uM= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id d550583e712d362a; Wed, 04 Nov 2026 14:20:23 +0000 X-Mizu-Trace-ID: d550583e712d362a X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Aditya Garg X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 (1.0) Subject: Re: [PATCH v4] drm/amd/pm: defer UCLK DPM on selected Apple Navi GPUs Date: Wed, 4 Nov 2026 19:50:05 +0530 Message-Id: References: Cc: Ed Schofield , atharvatiwarilinuxdev@gmail.com, dev@deq.rocks, alexander.deucher@amd.com, kenneth.feng@amd.com, christian.koenig@amd.com, airlied@gmail.com, simona@ffwll.ch, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org In-Reply-To: To: Alex Deucher X-Mailer: iPad Mail (24B119) > On 4 Nov 2026, at 7:37=E2=80=AFPM, Alex Deucher wr= ote: >=20 > =EF=BB=BFOn Wed, Nov 4, 2026 at 7:52=E2=80=AFAM Ed Schofield wrote: >>=20 >> Hi Alex, hi Atharva, hi all, >>=20 >> Alex, I'd like to withdraw my September v4 submission. I also don't suppo= rt >> applying v5 as posted or the simplified patch you attached later in this >> thread. Please remove my Co-developed-by and Signed-off-by tags from both= >> versions. I no longer think deferring UCLK is the right approach for the i= Macs. >>=20 >> I also excluded the MacBookPro16,1 (020f) from v4 deliberately because a t= ester >> found that with deferred UCLK it still hung after login, as it does witho= ut the >> patch [1], which seems to fit Andr=C3=A9's PPTable diagnosis. >>=20 >> Since then, I've been working with Atharva to get his native-5K iMac supp= ort >> upstream. His patch initializes the display before the SMU, which has als= o >> prevented the boot failures without deferring UCLK. On my iMac20,1 (0218)= , 13 >> of 20 warm boots failed with the upstream order; with display first, all 4= 0 >> boots passed [4]. Another tester reported one warm and one cold boot, bot= h >> successful, on a 0219 [2]. On an iMac20,2 (021a), changing only the >> initialization order improved warm boot success from 11 out of 20 to 100 o= ut of >> 100 [3]. His patch only applies to the iMac20,1 and iMac20,2, so it doesn= 't fix >> the 16,1 either. >>=20 >> I don't think the iMacs and the MacBookPro16,1 have the same problem. The= >> iMacs fail while amdgpu is loading: the SMU stops responding to >> EnableAllSmuFeatures (message 6), and the probe fails with -62. With the >> display initialized first, the same message succeeds with UCLK included, >> and the iMac boots normally. The 16,1 loads amdgpu without errors and han= gs >> later, after login, with or without deferred UCLK [1]. So deferring UCLK >> seems to help the iMacs only because it moves the enable after display >> init, and it doesn't help the MacBookPro16,1. >>=20 >> I have prepared a draft patch with Atharva as author and me as co-develop= er, >> incorporating his review feedback. It combines display-first initializati= on and >> native 5120x2880 support through two tiled connectors with suspend/resume= and >> display power-management changes. The current draft is here: >>=20 >> https://github.com/edschofield/linux-t2-patches/blob/7273823e425200e9f371= e9272e02ebf9abb6f1c2/7003-amdgpu-add-support-for-5K.patch >>=20 >> This has passed some initial automated testing on my iMac20,1 but I need t= o do >> more testing and get Atharva's final review and sign-off. >=20 > There are already patches on the list to support the 5K Macs: > https://lists.freedesktop.org/archives/dri-devel/2026-November/610011.html= Those patches are for older non T2 iMacs. We are discussing iMac20,1 and 20,= 2 which are T2 Macs. >=20 > Alex >=20 >>=20 >> Alex, thanks for following up on the boot issue and checking with the Win= dows >> team. >>=20 >> Best regards, >> Ed >>=20 >> [1] https://github.com/t2linux/linux-t2-patches/pull/61#issuecomment-5646= 139127 >> [2] https://github.com/t2linux/wiki/issues/743#issuecomment-6083265811 >> [3] https://github.com/t2linux/wiki/issues/743#issuecomment-6131809640 >> [4] https://github.com/t2linux/wiki/issues/743#issuecomment-6163146905