From nobody Tue Jun 30 09:22:48 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A520C433EF for ; Sun, 23 Jan 2022 09:05:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236025AbiAWJFz (ORCPT ); Sun, 23 Jan 2022 04:05:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232321AbiAWJFy (ORCPT ); Sun, 23 Jan 2022 04:05:54 -0500 Received: from mail-qk1-x72d.google.com (mail-qk1-x72d.google.com [IPv6:2607:f8b0:4864:20::72d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8E0AC06173B for ; Sun, 23 Jan 2022 01:05:53 -0800 (PST) Received: by mail-qk1-x72d.google.com with SMTP id g145so709016qke.3 for ; Sun, 23 Jan 2022 01:05:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=eX3+DBLJl7kPGzkIiPqLhVq9cTOZ0N88Avq3dcptuxU=; b=btmtA6Grf+PXkdfiNHYWykZ3RTKbJes6CDtpN2wUTw+raLCpy1PI/WGx1QbXYe5YZN 2Aef5zrFSy7BX6ykz1tQXpqVS3EoUaS5Mbm6vru5TLHAOt7/S1qARMCLv6H7eyoDSh9c tZSTeyJYCW8J1gjUgLbWrDRuDzUkvBJT4W/fQcjJntnroAxIrHyo+U2Rugg+bpqQ+Obt bdkvZJQzj26DpyZ9cNsZUvdA3kU6UAuEvOA0Laa9M+7/VPrMw+BA1J8F3iKHwTpIaZ82 OyarFOi4fGvmZB6MaNCBLuCTeibKZa9P/kjLyMrIruqKJ1e8gpiqOIPvKARh6+i7wFPv NpWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=eX3+DBLJl7kPGzkIiPqLhVq9cTOZ0N88Avq3dcptuxU=; b=FkA9oONqDy6HtYRT67c1MnOLA1n7NsgvdJajcSaa0KsCAriJzuVVLVAMCEoI759WSp Vnkn1Z/j51sqjA2+ItgmLriOBhPC0NRpt7Yd/zzTa6NyvGpreL6aKy9rMDryv8A3ErZN g4sl6f5U10M7X+Unhn5PTFJGC3gmoY4GJ0kSCeFwKoqN8AlLFuU1oNV0GgyqA+e56C38 R3b/OPBmJtV6EdE6x+O7EuU5k3A0MSCR7blkRfqyq0r48/dLiRG3T7OmknXLkYjZnit3 goqjD2XY5hIXSkiyqZSAAcPm/OFdij8OucnrKEjvB4pPF3XCvH0yFX9hwz6EukE6Y6mU cEhw== X-Gm-Message-State: AOAM532s8lQTmtzYnS3wHtyPzek5zXJmY2U7YqNkbQIGUPvBGvWoFIx0 9VBX8BqCQ2wozgUidoWOPUA= X-Google-Smtp-Source: ABdhPJzY2JqV02cUZ1vxb0vczI+ycvCGtFWFwVcB4D0aRymmcH5Ck2jcJ5vsH2fj06H+x1FSMM5Y7A== X-Received: by 2002:a05:620a:1663:: with SMTP id d3mr7803665qko.199.1642928752563; Sun, 23 Jan 2022 01:05:52 -0800 (PST) Received: from tong-desktop.local (99-105-211-126.lightspeed.sntcca.sbcglobal.net. [99.105.211.126]) by smtp.googlemail.com with ESMTPSA id y2sm5558080qke.33.2022.01.23.01.05.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 23 Jan 2022 01:05:52 -0800 (PST) From: Tong Zhang To: Hans de Goede , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Tong Zhang Subject: [PATCH v1] drm/privacy-screen: honor acpi=off in detect_thinkpad_privacy_screen Date: Sun, 23 Jan 2022 01:05:48 -0800 Message-Id: <20220123090548.763170-1-ztong0001@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" when acpi=3Doff is provided in bootarg, kernel crash with [ 1.252739] BUG: kernel NULL pointer dereference, address: 0000000000000= 018 [ 1.258308] Call Trace: [ 1.258490] ? acpi_walk_namespace+0x147/0x147 [ 1.258770] acpi_get_devices+0xe4/0x137 [ 1.258921] ? drm_core_init+0xc0/0xc0 [drm] [ 1.259108] detect_thinkpad_privacy_screen+0x5e/0xa8 [drm] [ 1.259337] drm_privacy_screen_lookup_init+0xe/0xe85 [drm] The reason is that acpi_walk_namespace expects acpi related stuff initialized but in fact it wouldn't when acpi is set to off. In this case we sould honor acpi=3Doff in detect_thinkpad_privacy_screen(). Signed-off-by: Tong Zhang --- drivers/gpu/drm/drm_privacy_screen_x86.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/drm_privacy_screen_x86.c b/drivers/gpu/drm/drm= _privacy_screen_x86.c index a2cafb294ca6..e7aa74ad0b24 100644 --- a/drivers/gpu/drm/drm_privacy_screen_x86.c +++ b/drivers/gpu/drm/drm_privacy_screen_x86.c @@ -33,6 +33,9 @@ static bool __init detect_thinkpad_privacy_screen(void) unsigned long long output; acpi_status status; =20 + if (acpi_disabled) + return false; + /* Get embedded-controller handle */ status =3D acpi_get_devices("PNP0C09", acpi_set_handle, NULL, &ec_handle); if (ACPI_FAILURE(status) || !ec_handle) --=20 2.25.1