From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 939B62EB11; Thu, 2 May 2024 17:34:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714671275; cv=none; b=J0/wF/FNfTGfcgGuZwR4gefTAEfmLCe3CGFBC/cmCQaCV9WuPim7IqxQ2Q+mip6erIPIKkKSFJN5LO25nUaNbihY1AOJdw9BY2mnkAys2PCAurJ3g7N//WB1OL/zacTrWYGO5XxN01LBFVKMkaJOm6eanXlIFVYy/j+un1sjnuw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714671275; c=relaxed/simple; bh=+h6/LR4S3cVJNgFoVugMFRRM6TloFW7Vi20pmrGxXpA=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=tbgs81kQ6r02IqCd2n5IYJwM5ZWUzBQSl2DMj0yjPlBD0T7BfmTvKt8MqtYS0waX70ouUYKx1kE3SmNPYroraHTWlDOHgiEytayeSs9z12MNtNUoTnXKgu2c/IiM54zUucR3VtKUWq6WTSmRkTPUWUq6EjSyp9AzYL48E4lz/TY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R+riW7/f; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R+riW7/f" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C236BC113CC; Thu, 2 May 2024 17:34:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714671275; bh=+h6/LR4S3cVJNgFoVugMFRRM6TloFW7Vi20pmrGxXpA=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=R+riW7/fdD2hN81bSLI10S63tn2cpLV+vVta5eOUQ4fDfRkhVXBnHu63P6rEAUEIM 04AyOXl3ocfyKC8w2Pmy9mZ+uxETyiA0gRPwU3pWRTZ1OT1HoJT4m0TKly2ztwdHXb bxGELm+ddNicgnUcbWDB8LMcf6tK3sI8hM0Do2r0zfg2FeHiiW8UjRo2K/AjqEYudY jD9UO/2W60isI8EPISQSzUv0ZzXnyBi/NWDK2RBbXARSCupZBjs8dxCBSAXRM4eoRB pezc+7FiUBOl/aWvh+1i70wNLE6Q0X54eX6ME0ZrzE0mzKk6FqnBmKvSMSUigIw1RT g+29fAd9TMsCA== Message-ID: <6af0488a5d845028978f57e63f3706f8899465cf.camel@kernel.org> Subject: Re: [PATCH 1/1] cxl/acpi.c: Add buggy BIOS hint for CXL ACPI lookup failure From: PJ Waskiewicz To: Dan Williams , Bjorn Helgaas Cc: linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 02 May 2024 10:34:33 -0700 In-Reply-To: <6632640bef65a_10c21294e3@dwillia2-mobl3.amr.corp.intel.com.notmuch> References: <20240429153138.GA681245@bhelgaas> <662fe860eb889_1487294e8@dwillia2-mobl3.amr.corp.intel.com.notmuch> <6632640bef65a_10c21294e3@dwillia2-mobl3.amr.corp.intel.com.notmuch> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.0-1 Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2024-05-01 at 08:47 -0700, Dan Williams wrote: > PJ Waskiewicz wrote: > > Buggy BIOS, that above value resolves to CX02.=C2=A0 In fact, it > > *should* be > > 49.=C2=A0 This is very much a bug in the ACPI arena. >=20 > Ok, so back to this patch in question, my concern with upgrading: >=20 > =C2=A0=C2=A0=C2=A0 dev_err(dev, "unable to retrieve _UID\n"); >=20 > ...to say "potentially buggy BIOS", is that same charge could be > levied > against all of the dev_warn() and dev_err() instances in > drivers/cxl/acpi.c. So, it's not clear to me that cxl_acpi driver > failures need to be more explicit. >=20 > Otherwise, pretty much any ACPI hiccup message in the kernel would be > candidate for claiming "BIOS is busted". I really do like your patch you proposed a few weeks back. I'm happy to pull that and test it if you'd like to move forward on that instead. Personally, I think the amount of discussion generated around this simple "the BIOS is broken" should warrant some level of change to help others not in-the-know to understand why their shiny new CXL devices fell over on init. Whatever that change looks like though, I'm not married to any particular approach. -PJ