From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0D6EC3F2D2 for ; Tue, 3 Mar 2020 02:57:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8865D217F4 for ; Tue, 3 Mar 2020 02:57:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583204233; bh=h8EAJl19Wp0HALYjFidwI9cUFJDeGchtkcXLkJUuArs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0OP+Kv5/QwdDV0bYnk1LYJwZbiZIH1I0JCX3bnh5ZPzqb9ZTZeG0tlvsySpAgIF9m HAUYOwzAitd3F6rX1L+w3YQGk9mKcJrdyQm2mcuaA3VV8dDnchvag1HX20Hm5Q+O25 IVwbRi1CaL4ETpgtjT20P9qr/aabmt/3M8mP+KI8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728616AbgCCC5L (ORCPT ); Mon, 2 Mar 2020 21:57:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:44266 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728426AbgCCCs2 (ORCPT ); Mon, 2 Mar 2020 21:48:28 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7CC4624680; Tue, 3 Mar 2020 02:48:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583203708; bh=h8EAJl19Wp0HALYjFidwI9cUFJDeGchtkcXLkJUuArs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BlBeneV3vp6Xjgc+i1hsUdP+h1505g1QE2Ek2sInORlFdpuEb7+aBOt2XPh4bYsAl G6pYz9lEQvQSYKh4ZNhbFkEJhw1rBskifToC73x6qHvR+4ZNEKHAp4yLOMRK3liY8S i2M94Oo8pKfDOqJjfrQvxq1AMqeuok04RusO7YlM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kai-Heng Feng , Alex Deucher , Joerg Roedel , Sasha Levin , iommu@lists.linux-foundation.org Subject: [PATCH AUTOSEL 5.4 39/58] iommu/amd: Disable IOMMU on Stoney Ridge systems Date: Mon, 2 Mar 2020 21:47:21 -0500 Message-Id: <20200303024740.9511-39-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200303024740.9511-1-sashal@kernel.org> References: <20200303024740.9511-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kai-Heng Feng [ Upstream commit 3dfee47b215e49788cfc80e474820ea2e948c031 ] Serious screen flickering when Stoney Ridge outputs to a 4K monitor. Use identity-mapping and PCI ATS doesn't help this issue. According to Alex Deucher, IOMMU isn't enabled on Windows, so let's do the same here to avoid screen flickering on 4K monitor. Cc: Alex Deucher Bug: https://gitlab.freedesktop.org/drm/amd/issues/961 Signed-off-by: Kai-Heng Feng Acked-by: Alex Deucher Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/amd_iommu_init.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index d7cbca8bf2cd4..b5ae9f7c0510b 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -2533,6 +2533,7 @@ static int __init early_amd_iommu_init(void) struct acpi_table_header *ivrs_base; acpi_status status; int i, remap_cache_sz, ret = 0; + u32 pci_id; if (!amd_iommu_detected) return -ENODEV; @@ -2620,6 +2621,16 @@ static int __init early_amd_iommu_init(void) if (ret) goto out; + /* Disable IOMMU if there's Stoney Ridge graphics */ + for (i = 0; i < 32; i++) { + pci_id = read_pci_config(0, i, 0, 0); + if ((pci_id & 0xffff) == 0x1002 && (pci_id >> 16) == 0x98e4) { + pr_info("Disable IOMMU on Stoney Ridge\n"); + amd_iommu_disabled = true; + break; + } + } + /* Disable any previously enabled IOMMUs */ if (!is_kdump_kernel() || amd_iommu_disabled) disable_iommus(); @@ -2728,7 +2739,7 @@ static int __init state_next(void) ret = early_amd_iommu_init(); init_state = ret ? IOMMU_INIT_ERROR : IOMMU_ACPI_FINISHED; if (init_state == IOMMU_ACPI_FINISHED && amd_iommu_disabled) { - pr_info("AMD IOMMU disabled on kernel command-line\n"); + pr_info("AMD IOMMU disabled\n"); init_state = IOMMU_CMDLINE_DISABLED; ret = -EINVAL; } -- 2.20.1