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 17BA6EB64DA for ; Fri, 16 Jun 2023 10:30:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344834AbjFPK3t (ORCPT ); Fri, 16 Jun 2023 06:29:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344621AbjFPK25 (ORCPT ); Fri, 16 Jun 2023 06:28:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BB1749D4; Fri, 16 Jun 2023 03:26:51 -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 F3B0F62B57; Fri, 16 Jun 2023 10:26:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CA2DC433C0; Fri, 16 Jun 2023 10:26:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686911210; bh=4p0Vti4pO3wKEPBOTQsKpppuMztsWz0eVXjJoFzOp1I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nWywZgySK5PMQN8NkWa4LTUT/sNlsKn/HfYBPrxOv96nc3wtm3Z2HQ+/onohCbqCY GE+r+4EMcJahgqQnvv8MnAndqJ0FkBhnoVpUaXZxW9S2iofqyc7GnOpRY7uIou6T6x esdZDsdChFaIbCFjz/IjLlMabw6rIOITkEVMsiBTmpcWMobiySXH2T6ADMHvK3CLr4 L7T2XON7lYEiwTwSz2yDyoWtCgQHC2v7KERijruh79d83U78XZTguM/zLzGVGeBlhv 6cEZxhVyx7KAH2O8Vv8cfNDT0/7WbSBT3AlQOtt/CLYSPtn8UI1EG2ZS1dBycrb+2E h9FVZ3ibZFuwg== 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 6.1 12/26] drm/ast: Fix modeset failed on DisplayPort Date: Fri, 16 Jun 2023 06:26:09 -0400 Message-Id: <20230616102625.673454-12-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230616102625.673454-1-sashal@kernel.org> References: <20230616102625.673454-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.34 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 1bc0220e6783e..38064e497b5d6 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1634,6 +1634,8 @@ 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; @@ -1642,9 +1644,17 @@ 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); @@ -1652,7 +1662,8 @@ 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