From patchwork Mon Mar 7 22:48:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 593661 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 606E31402D8; Tue, 8 Mar 2016 10:02:11 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ad4AB-0004df-St; Mon, 07 Mar 2016 23:02:07 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1ad41c-00080l-35 for kernel-team@lists.ubuntu.com; Mon, 07 Mar 2016 22:53:16 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ad41b-0000FV-LR; Mon, 07 Mar 2016 22:53:15 +0000 Received: from kamal by fourier with local (Exim 4.86) (envelope-from ) id 1ad41Y-0001xi-W0; Mon, 07 Mar 2016 14:53:12 -0800 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 4.2.y-ckt 101/273] drm/dp/mst: Reverse order of MST enable and clearing VC payload table. Date: Mon, 7 Mar 2016 14:48:12 -0800 Message-Id: <1457391064-6660-102-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457391064-6660-1-git-send-email-kamal@canonical.com> References: <1457391064-6660-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Cc: Andrey Grodzovsky , Kamal Mostafa , Dave Airlie X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 4.2.8-ckt5 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Andrey Grodzovsky commit c175cd16df272119534058f28cbd5eeac6ff2d24 upstream. On DELL U3014 if you clear the table before enabling MST it sometimes hangs the receiver. Signed-off-by: Andrey Grodzovsky Reviewed-by: Harry Wentland Acked-by: Alex Deucher Signed-off-by: Dave Airlie Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/drm_dp_mst_topology.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 0ec9ad5..2c691b3 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1969,6 +1969,12 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms mgr->mst_primary = mstb; kref_get(&mgr->mst_primary->kref); + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, + DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); + if (ret < 0) { + goto out_unlock; + } + { struct drm_dp_payload reset_pay; reset_pay.start_slot = 0; @@ -1976,12 +1982,6 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms drm_dp_dpcd_write_payload(mgr, 0, &reset_pay); } - ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, - DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); - if (ret < 0) { - goto out_unlock; - } - /* sort out guid */ ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);