From patchwork Thu May 25 01:29:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jammy Huang X-Patchwork-Id: 13254668 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A4BFBC77B73 for ; Thu, 25 May 2023 01:29:31 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CC3E210E0AB; Thu, 25 May 2023 01:29:30 +0000 (UTC) Received: from mail.aspeedtech.com (mail.aspeedtech.com [211.20.114.72]) by gabe.freedesktop.org (Postfix) with ESMTPS id 038AE10E625 for ; Thu, 25 May 2023 01:29:27 +0000 (UTC) Received: from JammyHuang-PC.aspeed.com (192.168.2.115) by TWMBX02.aspeed.com (192.168.0.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 25 May 2023 09:29:21 +0800 From: Jammy Huang To: , , , Subject: [PATCH v2] drm/ast: Fix modeset failed on DisplayPort Date: Thu, 25 May 2023 09:29:18 +0800 Message-ID: <20230525012918.11918-1-jammy_huang@aspeedtech.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [192.168.2.115] X-ClientProxiedBy: TWMBX02.aspeed.com (192.168.0.24) To TWMBX02.aspeed.com (192.168.0.24) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" If we switch display and update cursor together, it could lead to modeset failed because of concurrent access to IO registers. Add lock protection in DP's edid access to avoid this problem. Signed-off-by: Jammy Huang Reviewed-by: Thomas Zimmermann --- v2 changes: - Fix build error since new struct ast_device is used. --- drivers/gpu/drm/ast/ast_mode.c | 11 +++++++++++ 1 file changed, 11 insertions(+) base-commit: 933174ae28ba72ab8de5b35cb7c98fc211235096 diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 36374828f6c8..9fcbf540d6fc 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1647,6 +1647,8 @@ static int ast_dp501_output_init(struct ast_device *ast) static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector) { void *edid; + struct drm_device *dev = connector->dev; + struct ast_device *ast = to_ast_device(dev); int succ; int count; @@ -1655,10 +1657,18 @@ static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector) if (!edid) goto err_drm_connector_update_edid_property; + /* + * Protect access to I/O registers from concurrent modesetting + * by acquiring the I/O-register lock. + */ + mutex_lock(&ast->ioregs_lock); + succ = ast_astdp_read_edid(connector->dev, edid); if (succ < 0) goto err_kfree; + mutex_unlock(&ast->ioregs_lock); + drm_connector_update_edid_property(connector, edid); count = drm_add_edid_modes(connector, edid); kfree(edid); @@ -1666,6 +1676,7 @@ static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector) return count; err_kfree: + mutex_unlock(&ast->ioregs_lock); kfree(edid); err_drm_connector_update_edid_property: drm_connector_update_edid_property(connector, NULL);