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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 9459BC433DB for ; Fri, 25 Dec 2020 11:20:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B35923129 for ; Fri, 25 Dec 2020 11:20:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729144AbgLYLUQ (ORCPT ); Fri, 25 Dec 2020 06:20:16 -0500 Received: from mail-m964.mail.126.com ([123.126.96.4]:58146 "EHLO mail-m964.mail.126.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725873AbgLYLUQ (ORCPT ); Fri, 25 Dec 2020 06:20:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=From:Subject:Date:Message-Id; bh=En7Gpmtc3/wWaw6Atp RnRmYZe/wcAcBFc8FpXL5uPMY=; b=SiyivXHvZeIi6ImxAmSsi4uPvt6ScNra+S 7cpM16wxNI/bd8OA3azXi3MuPZ0jgGJ8z8LxIIoQa2W41RWQoFEGDRjA/pf4rYx+ /hU82RRyv+/mZnnWQJLnZgJCk00uzAUGHnrGwtugz3fnAsTXNlvFG7jW0fahxxyb lMGZ2nqJY= Received: from localhost.localdomain (unknown [36.112.86.14]) by smtp9 (Coremail) with SMTP id NeRpCgB3L3o1n+VfBUQrQA--.7179S3; Fri, 25 Dec 2020 16:13:45 +0800 (CST) From: Defang Bo To: airlied@linux.ie, daniel@ffwll.ch Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Defang Bo Subject: [PATCH 2/2] drivers/gpu/drm/ast: Fix infinite loop if read fails Date: Fri, 25 Dec 2020 16:13:34 +0800 Message-Id: <1608884014-2327765-2-git-send-email-bodefang@126.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1608884014-2327765-1-git-send-email-bodefang@126.com> References: <1608884014-2327765-1-git-send-email-bodefang@126.com> X-CM-TRANSID: NeRpCgB3L3o1n+VfBUQrQA--.7179S3 X-Coremail-Antispam: 1Uf129KBjvdXoWrKrWDAw1UKrWrGFy8KFy3Jwb_yoWDtFg_Cr 1rXr9xW34qy3Zrur1jya15ZrZF9a1j9rZ5X3W7KayfAr18ArsIq3409rykAr4UW3ZrZFZ8 Xa1kWry5Jr1fKjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IUj8sqtUUUUU== X-Originating-IP: [36.112.86.14] X-CM-SenderInfo: pergvwxdqjqiyswou0bp/1tbiExkG11pD+-BOsgAAs1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Why] Similar to commit <298360af3> ast_init_dram_reg() configures a window in order to access BMC memory. A BMC register can be configured to disallow this, and if so, causes an infinite loop in the ast driver which renders the system unusable. [How] Fix this by erroring out if an error is detected. Signed-off-by: Defang Bo --- drivers/gpu/drm/ast/ast_post.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c index ef19c70..86e4d23 100644 --- a/drivers/gpu/drm/ast/ast_post.c +++ b/drivers/gpu/drm/ast/ast_post.c @@ -302,13 +302,13 @@ static void ast_init_dram_reg(struct drm_device *dev) ast_write32(ast, 0x12000, 0x1688A8A8); do { if (pci_channel_offline(dev->pdev)) - return -EIO; + return -EIO; } while (ast_read32(ast, 0x12000) != 0x01); ast_write32(ast, 0x10000, 0xfc600309); do { if (pci_channel_offline(dev->pdev)) - return -EIO; + return -EIO; } while (ast_read32(ast, 0x10000) != 0x01); } -- 2.7.4