From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E54F4283FD9 for ; Tue, 14 Apr 2026 18:39:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776191969; cv=none; b=hKPpGVDSdG6jd/L2hhitVRrqM0wTF1cjA0BcUztU9VRu+fzVZktCLFbSZyGM0ckrKsire0d+3lzRyChVCPj5ilWclFbEK8HJZCRrbfCB6LuwCFO27PbgQpDr7H8Q7F5AEMpb5qry+7LG1y0aKV0Jvd5L8DBWt28i+z4rtS3mEZI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776191969; c=relaxed/simple; bh=Al22eCsPrDMWwuzUlQzmULHU1hnnVnLvohxy1An8XkY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DlCHHZzmTP09/SfDeWPm05UGLXLrW0htu9MMorpqHRK+bcCa81XoAJnVljVT5DVc4mnAln6iku9hZdMwG4eJr7Ty8SMpsRQl9H/VCFaQr8T9TQYhjFWfcpxrD1TZmLbWckgh7KAHO7T5Ko/klBXBg42kbrYtJc2hjwSCzb4bjMg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com; spf=pass smtp.mailfrom=baylibre.com; dkim=pass (2048-bit key) header.d=baylibre-com.20251104.gappssmtp.com header.i=@baylibre-com.20251104.gappssmtp.com header.b=E+dWKydH; arc=none smtp.client-ip=209.85.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baylibre.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20251104.gappssmtp.com header.i=@baylibre-com.20251104.gappssmtp.com header.b="E+dWKydH" Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-488e1a8ac40so48314435e9.2 for ; Tue, 14 Apr 2026 11:39:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20251104.gappssmtp.com; s=20251104; t=1776191966; x=1776796766; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=QDqOVJTUyVa1BVmErQMnVWTnNiaUpnAIeTBw2pAF2g4=; b=E+dWKydH8jWC1AEI+ukNI/3tIVptUivDQReEIL9RW4uDvqx3aZuBxnes5CZcF22cO2 4IohEW3l4wBnbdBN8Bye5lscRj2Y46LK7cpU/Bf37f+UrOQ7iAELwprrWKIgJRB0fOda lKTysCU1CuMlkILseO7i2NL7eELBVkaODh70TYTxXqczGK9YBiXqDdMckp9l+7pJklR+ HupjfYX6v408d7Jf6oTA96QWT7nhl6myyAl9sUaGBl8KcJ2MWL7MapoIgvmNfV4tKHax QP+n0Ok1xcVCpQhTv7TAR3kP/zslLrl3KH3VFpfdPohubK+2oZcuuNdTsONg4VpRta/1 fAQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776191966; x=1776796766; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=QDqOVJTUyVa1BVmErQMnVWTnNiaUpnAIeTBw2pAF2g4=; b=U+6nm1XWLt1mPl3advUrpktz7oSmgwc3EQzZUxuvUmgIuRAkZ4Q+Pnd2AvAzKzYcpG Jq74lzgysNX6CvzVLLSdJa3gfHBo1i0FajUOZTNlZPG2ry49jwXNFPUt18il5vJXpH+R 8CvJPIxkafo16awvTKdc8v9TmJ5VmUZTtuzqZSniHMJRCGtNPcR5GbVPDpPR5NBBsZ0M 426265Pn8buaORXvCsGpPdFuyj8dqW8buIYlOdNLzifqOigS1IZKjP1Vk6zYoV2W+8Jy Ja3WC+lKnitnCKtlYowDaylc6pjcDHcM6eBkJehMgUwXOXG5lYCoaPt+KcoQUxwWsgl+ /yBQ== X-Forwarded-Encrypted: i=1; AFNElJ+SgUvsh4mJJolEqWaDrjWo5EPT6VIirTSE5tkydB/JYw7jC8U+JpL8KUDfs2jH7f5zFncB4DPJ2C4fSZs=@vger.kernel.org X-Gm-Message-State: AOJu0YzPhFYmx+apDcKWDfIFsVuloXrQVQKYJL/bbodVPm3eVVFtlTIK IOD90MNL7Io4MVHC1yLYdoUrsdhkZe7IhCzLGCoBqQxN6ZnhBeTXNZSS/o2qlPgHQhA= X-Gm-Gg: AeBDietNVwmN8SkLU9iL52AZ9LMFlGnJ7P+zoia73SIECXcZXmy+BwOmHAXRbqZga9U +GJC+Nm0IcvYcfq+BOszHoM/MWiogVX084jsNg9DtE2qh3ZhnUOkl9BnmiYk+bFMOIVA8ufdXBo OHxhNzD5r6wlcTj2sQBzawUfCNZBlsERlalqo0d2zGXDSBuElS65MJccfvRtRAc7PIEdIf/F+Cb LBEKPSLaEh0PMql+ZVQyTOBnAr43118C7ttHXAMoFQYDYh80CY+0GO3kvrQPsN3A2NREtfWPgb9 78pd7Vm3Q9utRTqMW7VouS7vYasQhj3EFQ1X+zPPVko3sqzmsWKqLP3h2fTyyCl1jv7NsU9ZLav wUf4qzIpoww1GERsW8s8ob2EPp+43GBM+/CH5mYIS7NfJBitdbSM+zLGhHDCtHp00UWnOMJMbWb tC9R7XzKJDPXzeL1M6d2wl85sBXfPXbwGPgtXP57HgJ4fspClqTTiAgUJtdd+EZWR4uSq5Xsilt 0IpGzLItQdLlA== X-Received: by 2002:a05:600c:46d0:b0:485:40c6:f507 with SMTP id 5b1f17b1804b1-488d689dbfcmr264013605e9.30.1776191966269; Tue, 14 Apr 2026 11:39:26 -0700 (PDT) Received: from localhost (p200300f65f20eb08ef305da4f44807a2.dip0.t-ipconnect.de. [2003:f6:5f20:eb08:ef30:5da4:f448:7a2]) by smtp.gmail.com with UTF8SMTPSA id 5b1f17b1804b1-488ede15694sm118371645e9.3.2026.04.14.11.39.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Apr 2026 11:39:25 -0700 (PDT) Date: Tue, 14 Apr 2026 20:39:24 +0200 From: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= To: Danilo Krummrich , Linus Torvalds Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Saravana Kannan , Andrew Morton , driver-core@lists.linux.dev, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [GIT PULL] Driver core changes for 7.0-rc1 Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="blufdf4hg3r3mn2j" Content-Disposition: inline In-Reply-To: --blufdf4hg3r3mn2j Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [GIT PULL] Driver core changes for 7.0-rc1 MIME-Version: 1.0 Hello, On Sat, Feb 28, 2026 at 11:44:25PM -0800, Linus Torvalds wrote: > On Wed, 11 Feb 2026 at 15:04, Danilo Krummrich wrote: > > > > Driver core changes for 7.0-rc1 > > > > - Bus: > > - Ensure bus->match() is consistently called with the device lock held >=20 > So I'm coming back to this, because it turns out this sounds like a > horrible mistake in the end. >=20 > You document it as being about consistent locking, but it appears this > change is what made the "firewire oops at driver attach" turn an oops > into just a silently dead machine. >=20 > In other words, it makes fragile drivers go from "you get an oops" to > something much worse. The oops becomes unrecoverable - with typically > a black screen at boot - because the probe is holding a lock that then > makes everything else come to a grinding halt when the driver fails. >=20 > And yes, this obviously only happens for buggy driver and doesn't > matter for _correct_ code, but about half of the kernel code is > drivers, and that half of the kernel code is also the typically the > most badly tested and often questionably implemented half. I have a machine here (stm32mp135f-dk, ARCH=3Darm) that fails to boot with dc23806a7c47 ("driver core: enforce device_lock for driver_match_device()"), but doesn't oops on dc23806a7c47^. (Fails to boot =3D no kernel messages on console.) I didn't try to debug that yet, but I wonder if that is an understood problem of said commit. I know that the commit was reverted in the meantime (and the machine boots fine on 9de68394a615 ("Revert "driver core: enforce device_lock for driver_match_device()""), but does that mean that there is a driver involved that somehow violates driver core assumptions and should be fixed even without the consistent locking? Hints about how to approach the issue (if there is any) welcome. Best regards Uwe --blufdf4hg3r3mn2j Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEP4GsaTp6HlmJrf7Tj4D7WH0S/k4FAmneidkACgkQj4D7WH0S /k7mDAgAj2QD1GrgaK+tSN/eZXXN/Qh33Q0fcE5ECUYjXCEQOQ1/Q0PENWiMEJcD 1JcKF8Jak0kMclC6LLwAc7RiVYQR5DZJ78BQlqh4ztLmBpVBr5SOiUTIyL2MvyCX xcuO3DWSQkpoBCzBxLHaRyLUkg4lpkI+YG4iasQkeia77K+wwr3CHzcLtUJmPuJM hN/GwawWf+pCjemuKj1tDv1dzLcXfA7LKVfqG8cGiDj6YXzAI3rXHvAjRZlyYde5 +4ajajrBgskzGi17QNymTyCwO4+5i+lOvyio54/wW/C+zZuzKC6e+nKoGdhEonFZ xuh+AtnOD5zUXWOPg4Xsmk4tqnno0Q== =0NgR -----END PGP SIGNATURE----- --blufdf4hg3r3mn2j--