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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9D9AC4CEC5 for ; Fri, 13 Sep 2019 13:32:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A20B120717 for ; Fri, 13 Sep 2019 13:32:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568381550; bh=/tMcsQLJXwZCavsk4/LHrnvm30ckf20vWoFTw+/AAVo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YZiKtjJS7UAIBr/SS6Txxa+u+xmz+0Nlw0ZyCoWvToRq2NLqul/mFv1IMvFU/Mtil tktlNoMAl4AVgCC7tuSQhbPHEUiaZ0pBdrC6TNRg2yLoHyidtkDbSfk3DUFls0C2wb 7mY0AsaKBO1AVP4EusSZ3yBovAFgXMOBHx2QS14A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389278AbfIMNNL (ORCPT ); Fri, 13 Sep 2019 09:13:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:38718 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388696AbfIMNNH (ORCPT ); Fri, 13 Sep 2019 09:13:07 -0400 Received: from localhost (unknown [104.132.45.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F066D208C0; Fri, 13 Sep 2019 13:13:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568380386; bh=/tMcsQLJXwZCavsk4/LHrnvm30ckf20vWoFTw+/AAVo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YUQ8OCdMz0ngyQGIOuVf6zBqQC3jUk0qpcJRBUvojZqKc6etWmunucllU+skDEqcQ 2UlL9UAuE3z/wASx38cjyhzg4NtovVWMRXPQzzNvPzkBK5/lkJfVH4p16crsET9h05 uGkov+f0kDYm7SMcAv76YewYWeF1uMJOErtSvVRA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lyude Paul , Jan-Marek Glogowski , Sasha Levin Subject: [PATCH 4.19 030/190] drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse" Date: Fri, 13 Sep 2019 14:04:45 +0100 Message-Id: <20190913130602.044100904@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190913130559.669563815@linuxfoundation.org> References: <20190913130559.669563815@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 3cf71bc9904d7ee4a25a822c5dcb54c7804ea388 ] This re-applies the workaround for "some DP sinks, [which] are a little nuts" from commit 1a36147bb939 ("drm/i915: Perform link quality check unconditionally during long pulse"). It makes the secondary AOC E2460P monitor connected via DP to an acer Veriton N4640G usable again. This hunk was dropped in commit c85d200e8321 ("drm/i915: Move SST DP link retraining into the ->post_hotplug() hook") Fixes: c85d200e8321 ("drm/i915: Move SST DP link retraining into the ->post_hotplug() hook") [Cleaned up commit message, added stable cc] Signed-off-by: Lyude Paul Signed-off-by: Jan-Marek Glogowski Cc: stable@vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20180825191035.3945-1-lyude@redhat.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/i915/intel_dp.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index f92079e19de8d..20cd4c8acecc3 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4739,6 +4739,22 @@ intel_dp_long_pulse(struct intel_connector *connector, */ status = connector_status_disconnected; goto out; + } else { + /* + * If display is now connected check links status, + * there has been known issues of link loss triggering + * long pulse. + * + * Some sinks (eg. ASUS PB287Q) seem to perform some + * weird HPD ping pong during modesets. So we can apparently + * end up with HPD going low during a modeset, and then + * going back up soon after. And once that happens we must + * retrain the link to get a picture. That's in case no + * userspace component reacted to intermittent HPD dip. + */ + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base; + + intel_dp_retrain_link(encoder, ctx); } /* -- 2.20.1