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=1794436235; b=pl9i4Y+D8GiOpcxrU5CcMN2TH3lgTzfe8/2stqoWNKX4H0uJH0J6bN+FWO7C0T/cowtM POyWDxsO05mcSMcH2W4VIBP4kpiCjuQ7gAoaB6KLjjog1dAEmN8NtbPJmq0YhClegKmt/ uDUHzhYXX0ul7KwxeMCsxABTTL3wnp5J2jFTqKeg+1M1Fyqv2RXSir8+PdQoQ3wX2/HtJ PeGNFf8RmAoeVaugMOAa5Y/iD6cof3UKL2tEaiU3XJ9VKk/aX1g/L+pliDmAfFmtEOMfH ms3VE10gHhDM/U9t5c7zJvolYHxEHXXFoVFYcpGo8HBTGIQzJTx4QWHm03uK+r1sIjg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794436235; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=srInJ1lFttHBxQxY+VpLS4HIIUibvm9Rc8ekjajKEn0=; b=T8YYgmf6xreiBcp5eeMJwS4Oen6ULGsUyw6z2T3t1/axxc6k0hLEWDICWBX6c1o0xZGZ BwkaH9iuW0KNzjM14L5h9HCm2gRE/5UH9TVWx6tCWx9/+uPryd4rACCHX73t3wAUmBMzm NjLVIQdKCjk7fWAYbT70U2g9xYQZQ4ZqC1AJNSfYIgJYPhA7waWXBQAlQ2LdXYdvvsw1H r1RacUQ4BXBP00AWEG8Kl8Bkxt1ba1VnBD1xOfebsnFfDTwWv55EhBsdcA1RnRiNXx7Al 2VE5FAt5lc4kXq2mR/w6OLJsYGfGV7i2hAABq4Paw9honf/ZyWiTFlYJHkp+HGQ3NRA== 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=k7ZH5nzw; 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 UTF8SMTPS id A2B66606A333; Wed, 11 Nov 2026 22:30:35 +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=k7ZH5nzw Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 034FB1F00A06; Wed, 11 Nov 2026 22:30:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794436235; bh=srInJ1lFttHBxQxY+VpLS4HIIUibvm9Rc8ekjajKEn0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=k7ZH5nzwqYIfvrDQEzyyLu6+KZ3xKazppHoXM5EP339KqOV6fG/GxYeoiSphdvnBJ QG8RMzqybUTQxPnGBF2ztZpbjCcUCe7qq8dOmQgU27HS3UgNRPX2D2MGsXDiGnh6ca pMY7McUMDUOjOQnwaOKXwgrUNO2iX+H+7lznG+U8Cx4Z4zTWWOqYCddhywwOPZcO00 2xMOGVbhW1vh+MpxavKOdgHKyHmSBfnBwSISFRUVip+wJHMWhk3UfFIC0SQ+8gM+zj a/5T1jytDV+KncNF7PMkardjaGSlhFyrixbpRFiYwZRPnJeeUpThnKPri/Z7o1WfjK Nwf/dPxih4cvQ== Date: Thu, 12 Nov 2026 00:30:31 +0200 From: Jarkko Sakkinen To: Breno Leitao Cc: Peter Huewe , Jason Gunthorpe , linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, surenkj@amazon.com, noodles@meta.com, kernel-team@meta.com Subject: Re: [PATCH 0/2] tpm: Stop retrying TPMs that have stopped working Message-ID: References: <20261111-tpm_unresponsive-v1-0-42ac1b965eb9@debian.org> 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 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261111-tpm_unresponsive-v1-0-42ac1b965eb9@debian.org> On Wed, Nov 11, 2026 at 01:57:32AM -0800, Breno Leitao wrote: > On Meta's datacenter, given the size, TPMs that stop working write about > 54 million lines a day to the kernel log, because nothing in the kernel > gives up on them. > > Two cases make up nearly all of it. > > Some TPMs stop responding. Every command then fails only after the > transport timeout, while the hwrng thread and userspace keep sending > more. > > The goal is to retire TPM that are not properly working, similarly to > what was done for EFI in commit 4b2c033b5bc971 ("efi/runtime-wrappers: > retire the worker if a wedged call ever returns") > > This feature aim to disable the chip once its commands have kept timing, > instead of keeping it in this desolate state. > > Disabling the chip makes the failure explicit: the log gets one line > saying the TPM is disabled, and every later command fails at once > instead of timing out. > > A health-check daemon, such as machine checker, can then detect > the broken hardware and send the machine to repair. > > Signed-off-by: Breno Leitao > --- > Breno Leitao (2): > tpm: Disable a TPM that stops responding > tpm: Disable a TPM whose hwrng reads keep failing > > drivers/char/tpm/tpm-chip.c | 20 +++++++++++++++++++- > drivers/char/tpm/tpm-interface.c | 29 +++++++++++++++++++++++++++++ > include/linux/tpm.h | 3 +++ > 3 files changed, 51 insertions(+), 1 deletion(-) > --- > base-commit: 630059a5a632377b9b7b487baccde92b7ae1dd47 > change-id: 20261110-tpm_unresponsive-a5f71c1db026 > > Best regards, > -- > Breno Leitao > I think this good stuff so existential condition for having some changes to address these issues is fulfilled. I.e. debating the details through will likely lead to productive results :-) Br, Jarkko