From patchwork Thu Aug 20 23:22:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: bugzilla-daemon@bugzilla.kernel.org X-Patchwork-Id: 11727185 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8999F1392 for ; Thu, 20 Aug 2020 23:22:47 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 67A4020738 for ; Thu, 20 Aug 2020 23:22:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 67A4020738 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=bugzilla.kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9588F6E064; Thu, 20 Aug 2020 23:22:43 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id 526C56E064 for ; Thu, 20 Aug 2020 23:22:42 +0000 (UTC) From: bugzilla-daemon@bugzilla.kernel.org To: dri-devel@lists.freedesktop.org Subject: [Bug 208947] amdgpu DisplayPort won't recognize all display modes after 5.9 merges Date: Thu, 20 Aug 2020 23:22:41 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_video-dri@kernel-bugs.osdl.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: Video(DRI - non Intel) X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ckane@colemankane.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: drivers_video-dri@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" https://bugzilla.kernel.org/show_bug.cgi?id=208947 --- Comment #12 from Coleman Kane (ckane@colemankane.org) --- Ok I re-did the bisect and I think I found the actual commit that introduced the regression. I have confirmed this by generating a reverse-patch and then applying that to the latest staging-testing branch I had cloned at the beginning of the week, and I was able to use the newer kernel without the bug occurring. The bug appears to have been introduced by commit 3fd20292c2352660155bbc11736dd014b2fc6e98: diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c index 5cb7b834e459..1a3dbed3becb 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c @@ -1133,6 +1133,45 @@ static inline enum link_training_result perform_link_training_int( return status; } +static enum link_training_result check_link_loss_status( + struct dc_link *link, + const struct link_training_settings *link_training_setting) +{ + enum link_training_result status = LINK_TRAINING_SUCCESS; + unsigned int lane01_status_address = DP_LANE0_1_STATUS; + union lane_status lane_status; + uint8_t dpcd_buf[4] = {0}; + uint32_t lane; + + core_link_read_dpcd( + link, + lane01_status_address, + (uint8_t *)(dpcd_buf), + sizeof(dpcd_buf)); + + /*parse lane status*/ + for (lane = 0; lane < link->cur_link_settings.lane_count; lane++) { + /* + * check lanes status + */ + lane_status.raw = get_nibble_at_index(&dpcd_buf[0], lane); + + if (!lane_status.bits.CHANNEL_EQ_DONE_0 || + !lane_status.bits.CR_DONE_0 || + !lane_status.bits.SYMBOL_LOCKED_0) { + /* if one of the channel equalization, clock + * recovery or symbol lock is dropped + * consider it as (link has been + * dropped) dp sink status has changed + */ + status = LINK_TRAINING_LINK_LOSS; + break; + } + } + + return status; +} + static void initialize_training_settings( struct dc_link *link, const struct dc_link_settings *link_setting, @@ -1372,6 +1411,9 @@ static void print_status_message( case LINK_TRAINING_LQA_FAIL: lt_result = "LQA failed"; break; + case LINK_TRAINING_LINK_LOSS: + lt_result = "Link loss"; + break; default: break; } @@ -1531,6 +1573,14 @@ enum link_training_result dc_link_dp_perform_link_training( status); } + /* delay 5ms after Main Link output idle pattern and then check + * DPCD 0202h. + */ + if (link->connector_signal != SIGNAL_TYPE_EDP && status == LINK_TRAINING_SUCCESS) { + msleep(5); + status = check_link_loss_status(link, <_settings); + } + /* 6. print status message*/ print_status_message(link, <_settings, status); diff --git a/drivers/gpu/drm/amd/display/include/link_service_types.h b/drivers/gpu/drm/amd/display/include/link_service_types.h index 4869d4562e4d..550f46e9b95f 100644 --- a/drivers/gpu/drm/amd/display/include/link_service_types.h +++ b/drivers/gpu/drm/amd/display/include/link_service_types.h @@ -66,6 +66,8 @@ enum link_training_result { /* other failure during EQ step */ LINK_TRAINING_EQ_FAIL_EQ, LINK_TRAINING_LQA_FAIL, + /* one of the CR,EQ or symbol lock is dropped */ + LINK_TRAINING_LINK_LOSS, }; struct link_training_settings {