From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-24418.protonmail.ch (mail-24418.protonmail.ch [109.224.244.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 88CE078F52 for ; Mon, 12 May 2025 17:30:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=109.224.244.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747071060; cv=none; b=QMmwIhLFxprq6ZkR0Pbz0Aj0tItPKXh1c16oUkfQU51hBr9Whd0OvHi6U4mkr2+SRIEWFeW9SCL9coDYy2lZVlJ25AQEKHowABoaWta2Umjl8LjO++ZpcTDwjq1yF3d9IXyZgcj2EXhR0pAy4JgbA+dCSyy+SHv+a1UDkCqEfZ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747071060; c=relaxed/simple; bh=E9ESfUj2WpfAG3ZXR2IjD+sEGB/Jc66yklwYO9G2ZtM=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QvEaUAIZqgH26cPombHC6fnlmnuaa5KSYfyj/MiRo2izMYznjXUhnoflQ2N0vJmyMZbkh6lWMirTkzgDeMLYAHpoilG8wSrYnWHcB++YBZrcTmwn5JUrIB5K+Ouahon3mAaOdFDEIWLMvD3Ewk5eRr10czAV+buxZXLYKkXkOio= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=proton.me; spf=pass smtp.mailfrom=proton.me; dkim=pass (2048-bit key) header.d=proton.me header.i=@proton.me header.b=hnU0z3mv; arc=none smtp.client-ip=109.224.244.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=proton.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=proton.me Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=proton.me header.i=@proton.me header.b="hnU0z3mv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=protonmail; t=1747071049; x=1747330249; bh=jZB1nicxWGlckxXy4g4z7NQCQ6SF2nkWYs9QJ8KThJg=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector:List-Unsubscribe:List-Unsubscribe-Post; b=hnU0z3mv0v1aQKbYN4eYUoAu1Cn2A0EOwpQz2VOqoUbf7FMZffgduPBswVNAg2bO1 AlIX8FUJlImsDUZIvAWZlveHZjnDkSsRD6JSolNg/sLCe/gEzRYTE4aKshjC9vQzjB /PKN5KM3sGFubVCVwYZEgXGM+9Y+zRRCz3hQaHuFJ/iqJKGEY0/8YldpLiJ/FHP5bP RoGHqM0F2D3qPPTcr/VYORXpO3tXWoeYQzRmg9A7mLEwMuGCJUGtzc0XaMQ2GXwzLg YRoGkltyvzu0+7qC1aCQ3SXdKVIpfWB1VTMuJ3hvygC7pDdXQdNXkDDATPvyammK4I p4iYIQXl8KVFQ== Date: Mon, 12 May 2025 17:30:45 +0000 To: Vignesh Raman From: dmkhn@proton.me Cc: Ingo Molnar , dmukhin@ford.com, mingo@redhat.com, andriy.shevchenko@linux.intel.com, x86@kernel.org, daniels , Daniel Stone , robdclark , lumag@kernel.org, linux-kernel Subject: Re: x86: Boot failure on select chromebooks with v6.15-rc5 Message-ID: In-Reply-To: <45450eeb-1866-4bf6-a83b-1f28e26f311c@collabora.com> References: <45450eeb-1866-4bf6-a83b-1f28e26f311c@collabora.com> Feedback-ID: 123220910:user:proton X-Pm-Message-ID: a49518909be0c153ec45816968a30cf2458eeb5e Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi,=20 On Fri, May 09, 2025 at 01:07:54PM +0530, Vignesh Raman wrote: > Hi Ingo, >=20 > On 09/05/25 12:07, Ingo Molnar wrote: > >=20 > > * Vignesh Raman wrote: > >=20 > > > > What boot cmdline does your kernel have? The MMIO-UART patches shou= ld > > > > only have an effect if the feature is specifically enabled via a bo= ot > > > > option: > > > >=20 > > > > + if (!strncmp(buf, "mmio32", 6)) { > > > > +=09=09=09buf +=3D 6; > > > > + early_mmio_serial_init(buf); > > > > + early_console_register(&early_serial_consol= e, keep); > > > > + buf +=3D 4; > > > > + } > > > >=20 > > >=20 > > > amdgpu:stoney: > > > earlyprintk=3Duart8250,mmio32,0xfedc6000,115200n8 console=3DttyS0,11= 5200n8 > > > root=3D/dev/nfs rw nfsroot=3D192.168.201.1:/var/lib/lava/dispatcher/t= mp/18598802/extract-nfsrootfs-wgn1xjer,tcp,hard,v3 > > > init=3D/init rootwait usbcore.quirks=3D0bda:8153:k ip=3Ddhcp > > > tftpserverip=3D192.168.201.1 > > >=20 > > > i915:amly: > > > earlyprintk=3Duart8250,mmio32,0xde000000,115200n8 console=3DttyS0,11= 5200n8 > > > root=3D/dev/nfs rw nfsroot=3D192.168.201.1:/var/lib/lava/dispatcher/t= mp/18598804/extract-nfsrootfs-5rlm_b6z,tcp,hard,v3 > > > init=3D/init rootwait usbcore.quirks=3D0bda:8153:k ip=3Ddhcp > > > tftpserverip=3D192.168.201.1 > > >=20 > > > i915:whl: > > > earlyprintk=3Duart8250,mmio32,0xde000000,115200n8 console=3DttyS0,11= 5200n8 > > > root=3D/dev/nfs rw nfsroot=3D192.168.201.1:/var/lib/lava/dispatcher/t= mp/18598833/extract-nfsrootfs-3w0w5_mi,tcp,hard,v3 > > > init=3D/init rootwait usbcore.quirks=3D0bda:8153:k ip=3Ddhcp > > > tftpserverip=3D192.168.201.1 > >=20 > > Well, if you remove the earlyprintk option then it will boot fine, > > right? >=20 > Yes, it works when mmio32 option is removed. >=20 > https://gitlab.freedesktop.org/vigneshraman/linux/-/jobs/76005338 >=20 > earlyprintk=3Duart8250,0xde000000,115200n8 console=3DttyS0,115200n8 > root=3D/dev/nfs rw nfsroot=3D192.168.201.1:/var/lib/lava/dispatcher/tmp/1= 8599938/extract-nfsrootfs-neuejjq0,tcp,hard,v3 > init=3D/init rootwait usbcore.quirks=3D0bda:8153:k ip=3Ddhcp > tftpserverip=3D192.168.201.1 For the above example, can you please try something like earlyprintk=3Dmmio32,0xde000000,nocfg ? In my case, configuring exact baud rate did not work. I started to dig that= , but did not finish, because `nocfg` worked (firmware happened to configure = the UART correctly). Using `nocfg` was sufficient for the system bringup debugg= ing. >=20 > >=20 > > The earlyprintk=3Dmmio32 in v6.15 is a new debugging feature that was > > tested on a single board by Denis Mukhin AFAIK, and it may or may not > > work on your particular UART - even assuming that all the parameters > > are correct. Correct, I have tested with one board only and with limited UART configurat= ion combinations. >=20 > So the earlyprintk=3Dmmio32 debugging feature is needed only for v6.15 an= d is > not necessary in previous kernels (e.g., v6.14 and earlier). Is my > understanding correct? >=20 > Regards, > Vignesh >=20 > >=20 > > Thanks, > >=20 > > =09Ingo >=20 Thanks, Denis