From patchwork Fri Mar 9 22:23:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Enric Balletbo i Serra X-Patchwork-Id: 10273755 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B589360594 for ; Sat, 10 Mar 2018 16:54:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A470C29173 for ; Sat, 10 Mar 2018 16:54:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 975402923C; Sat, 10 Mar 2018 16:54:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 32A3F29173 for ; Sat, 10 Mar 2018 16:54:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 879C66E35F; Sat, 10 Mar 2018 16:52:27 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5CBBB6EC42 for ; Fri, 9 Mar 2018 22:24:13 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 23C7227561A From: Enric Balletbo i Serra To: architt@codeaurora.org, inki.dae@samsung.com, thierry.reding@gmail.com, hjc@rock-chips.com, seanpaul@chromium.org, airlied@linux.ie, tfiga@chromium.org, heiko@sntech.de Subject: [PATCH v5 11/36] drm/bridge: analogix_dp: Wait for HPD signal before configuring link Date: Fri, 9 Mar 2018 23:23:02 +0100 Message-Id: <20180309222327.18689-12-enric.balletbo@collabora.com> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180309222327.18689-1-enric.balletbo@collabora.com> References: <20180309222327.18689-1-enric.balletbo@collabora.com> MIME-Version: 1.0 X-Mailman-Approved-At: Sat, 10 Mar 2018 16:51:59 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Laurent.pinchart@ideasonboard.com, ykk@rock-chips.com, kernel@collabora.com, m.szyprowski@samsung.com, linux-samsung-soc@vger.kernel.org, rydberg@bitmath.org, krzk@kernel.org, linux-rockchip@lists.infradead.org, kgene@kernel.org, linux-input@vger.kernel.org, orjan.eide@arm.com, wxt@rock-chips.com, jeffy.chen@rock-chips.com, =?UTF-8?q?St=C3=A9phane=20Marchesin?= , linux-arm-kernel@lists.infradead.org, mark.yao@rock-chips.com, wzz@rock-chips.com, hl@rock-chips.com, jingoohan1@gmail.com, sw0312.kim@samsung.com, dianders@chromium.org, kyungmin.park@samsung.com, Enric Balletbo i Serra , kuankuan.y@gmail.com, hshi@chromium.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: zain wang According to DP spec v1.3 chap 3.5.1.2 Link Training, Link Policy Maker must first detect that the HPD signal is asserted high by the Downstream Device before establishing a link with it. Cc: Stéphane Marchesin Signed-off-by: zain wang Signed-off-by: Sean Paul Signed-off-by: Thierry Escande Signed-off-by: Enric Balletbo i Serra Tested-by: Marek Szyprowski Reviewed-by: Archit Taneja --- drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index c81733b8185e..92fb9a072cb6 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1169,6 +1169,17 @@ static int analogix_dp_set_bridge(struct analogix_dp_device *dp) if (ret) goto out_dp_init; + /* + * According to DP spec v1.3 chap 3.5.1.2 Link Training, + * We should first make sure the HPD signal is asserted high by device + * when we want to establish a link with it. + */ + ret = analogix_dp_detect_hpd(dp); + if (ret) { + DRM_ERROR("failed to get hpd single ret = %d\n", ret); + goto out_dp_init; + } + ret = analogix_dp_commit(dp); if (ret) goto out_dp_init;