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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75A44EB64D7 for ; Fri, 16 Jun 2023 10:27:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231791AbjFPK1F (ORCPT ); Fri, 16 Jun 2023 06:27:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344129AbjFPK00 (ORCPT ); Fri, 16 Jun 2023 06:26:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 361943A9E; Fri, 16 Jun 2023 03:25:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 84E3762B57; Fri, 16 Jun 2023 10:25:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E54C3C433BD; Fri, 16 Jun 2023 10:25:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686911147; bh=ExstxKPrGbziirkucB5PqIckFETFvkocrqw85/Grcv4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VnTJ3de2zeV16ltBQyW4hUPjAz7PtnUC3L2sZD2/JuuIddWi3JspaPCmcKrzn8aWS g6EFtmKf0L1nEkC33Gv63ib/xMKF1uDFoGIFVPIGcVOwUvpizX1fd8j+FNb+hmecII y7fm+lSC6nRN6EMyDltq5DnsSI5jETufHhdmMHgb4MyC0Vpbc5/S9EZ3uXR+rCOhO4 9igg3OAZWdgmMO+nyqBKCaG/ZvLE5dvV0r7YnQesTQdWsPHp0BV8cuw2HHfv01sM4Y aAHhocB7zmLE0AWgNuCo2YHCrnwK1XR7qa0/xOZZBDuZ5wQt/WVLbV3XdGqTGW6tC1 XTKcZptHV0xfw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jammy Huang , Thomas Zimmermann , Sasha Levin , airlied@redhat.com, airlied@gmail.com, daniel@ffwll.ch, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.3 13/30] drm/ast: Fix modeset failed on DisplayPort Date: Fri, 16 Jun 2023 06:25:01 -0400 Message-Id: <20230616102521.673087-13-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230616102521.673087-1-sashal@kernel.org> References: <20230616102521.673087-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.3.8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jammy Huang [ Upstream commit 3692ababa322b4d9ffbd973865bc88018e896fcd ] 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. Reviewed-by: Thomas Zimmermann Signed-off-by: Jammy Huang Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20230601004847.1115-1-jammy_huang@aspeedtech.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/ast/ast_mode.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 984ec590a7e7d..e267cf9f505b9 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1635,6 +1635,8 @@ static int ast_dp501_output_init(struct ast_private *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; @@ -1643,9 +1645,17 @@ 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; + goto err_mutex_unlock; + + mutex_unlock(&ast->ioregs_lock); drm_connector_update_edid_property(connector, edid); count = drm_add_edid_modes(connector, edid); @@ -1653,7 +1663,8 @@ static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector) return count; -err_kfree: +err_mutex_unlock: + mutex_unlock(&ast->ioregs_lock); kfree(edid); err_drm_connector_update_edid_property: drm_connector_update_edid_property(connector, NULL); -- 2.39.2