From patchwork Sun Apr 7 21:05:26 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: PJ Waskiewicz X-Patchwork-Id: 13620289 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 16B8D3D576; Sun, 7 Apr 2024 21:05:51 +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=1712523952; cv=none; b=n7L2/Bs6ncvClcuuruVYmotZIjG/6AtN6FWxztzZkkctezNevFf0T+Rz6trd5YpuJNqxwrVd9TkU/x0u7URYOD3K1aocS5VBT7yD7RWthzLG3BoEFpu/UDVgwhhvDPwMetg3BM5iuVKFvcu3c+Zm21MxRx2Y2uu1jbkRB7Pgp8s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712523952; c=relaxed/simple; bh=alFJHuuY58av6Gpl72+zYmR9Fs+6674Zyv4hEKl/Gr4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=j9y6E47qUQVd9AlbnL7tAWFhHq5d6DBXRNq8MY+M3UMflV/jtAiCqaka4B96jP+IWVm5yyu9LEuYA5HeOOW1zHZNM3BujNd5m1WFlyktzTeMLmQztYXN56rKTlO+QzTHXCFFJvroBrhOD0xjCyVZcsgnVVPaD4a3oabtDZb5iaw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ii2PtuJF; 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="ii2PtuJF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58EE4C433F1; Sun, 7 Apr 2024 21:05:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712523951; bh=alFJHuuY58av6Gpl72+zYmR9Fs+6674Zyv4hEKl/Gr4=; h=From:To:Cc:Subject:Date:From; b=ii2PtuJFpxgQJTh561Dx4dKf2IWsrqB7TOMg3giuAc6P751oRKiTaQduKvfsUV2i0 G95vbPJrMhO1bG3Xns9BIO5qtkcJYOJIZgKvJLRQsohZGzAIR7SDFlF4iNVsduRlfA bM2DZl2S91YA4hPfQ/3ruXpVEnkuX0GRAueC9laW9qJTctWj2VRRUYRjM1VxvfVv0x OU5tEhI7hUi34qaJ71Y11o86wU5iAsZdBBX8ix6XvM+IpAekH54IyXcP3oRRqv7wJb BHFoxhovJtj9uvNxrRHuNrPXj+aumivwHZJ/CHKu+9G1ElskaE6RjgQ51A6x19OQ2Q t9TxeFgVF3Pkg== From: ppwaskie@kernel.org To: Dan Williams , linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org Cc: linux-kernel@vger.kernel.org, PJ Waskiewicz Subject: [PATCH 1/1] cxl/acpi.c: Add buggy BIOS hint for CXL ACPI lookup failure Date: Sun, 7 Apr 2024 14:05:26 -0700 Message-Id: <20240407210526.8500-1-ppwaskie@kernel.org> X-Mailer: git-send-email 2.40.1 Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: PJ Waskiewicz Currently, Type 3 CXL devices (CXL.mem) can train using host CXL drivers on Emerald Rapids systems. However, on some production systems from some vendors, a buggy BIOS exists that improperly populates the ACPI => PCI mappings. This leads to the cxl_acpi driver to fail probe when it cannot find the root port's _UID, in order to look up the device's CXL attributes in the CEDT. Add a bit more of a descriptive message that the lookup failure could be a bad BIOS, rather than just "failed." Signed-off-by: PJ Waskiewicz Signed-off-by: PJ Waskiewicz Reviewed-by: PJ Waskiewicz --- drivers/cxl/acpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index af5cb818f84d..56019466a09c 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -504,7 +504,7 @@ static int cxl_get_chbs(struct device *dev, struct acpi_device *hb, rc = acpi_evaluate_integer(hb->handle, METHOD_NAME__UID, NULL, &uid); if (rc != AE_OK) { - dev_err(dev, "unable to retrieve _UID\n"); + dev_err(dev, "unable to retrieve _UID. Potentially buggy BIOS\n"); return -ENOENT; }