From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 504358BE0 for ; Tue, 28 Mar 2023 14:45:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7AE8C433D2; Tue, 28 Mar 2023 14:45:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680014746; bh=nx/aY+vhKEi3XNXRCeA6aHx5EHKt59QZ1+YYRKfWj0g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y0z39okPSFjTBA3Gvb+Fmg+v6fsgCwgRqKeyp8H3psQ6ZckvMAn2gJP3OqdoxwzsU GJ+T7qDuEMOo+tF5SpZOYuOk6CZwUSp3oSHYRqYcjxdE2yiB15DFwsgZ2PsK+WtVxR 97W3zKrDnEIcaUqd2fGqtuPPba5L0eq7aYs1dX6Q= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mario Limonciello , Wenjing Liu , Qingqing Zhuo , Cruise Hung , Daniel Wheeler , Alex Deucher , Sasha Levin Subject: [PATCH 6.2 009/240] drm/amd/display: Fix DP MST sinks removal issue Date: Tue, 28 Mar 2023 16:39:32 +0200 Message-Id: <20230328142620.045093548@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230328142619.643313678@linuxfoundation.org> References: <20230328142619.643313678@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Cruise Hung [ Upstream commit cbd6c1b17d3b42b7935526a86ad5f66838767d03 ] [Why] In USB4 DP tunneling, it's possible to have this scenario that the path becomes unavailable and CM tears down the path a little bit late. So, in this case, the HPD is high but fails to read any DPCD register. That causes the link connection type to be set to sst. And not all sinks are removed behind the MST branch. [How] Restore the link connection type if it fails to read DPCD register. Cc: stable@vger.kernel.org Cc: Mario Limonciello Reviewed-by: Wenjing Liu Acked-by: Qingqing Zhuo Signed-off-by: Cruise Hung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit cbd6c1b17d3b42b7935526a86ad5f66838767d03) Modified for stable backport as a lot of the code in this file was moved in 6.3 to drivers/gpu/drm/amd/display/dc/link/link_detection.c. Signed-off-by: Mario Limonciello Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index 754fc86341494..54656fcaa6464 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -1016,6 +1016,7 @@ static bool detect_link_and_local_sink(struct dc_link *link, struct dc_sink *prev_sink = NULL; struct dpcd_caps prev_dpcd_caps; enum dc_connection_type new_connection_type = dc_connection_none; + enum dc_connection_type pre_connection_type = link->type; const uint32_t post_oui_delay = 30; // 30ms DC_LOGGER_INIT(link->ctx->logger); @@ -1118,6 +1119,8 @@ static bool detect_link_and_local_sink(struct dc_link *link, } if (!detect_dp(link, &sink_caps, reason)) { + link->type = pre_connection_type; + if (prev_sink) dc_sink_release(prev_sink); return false; @@ -1349,6 +1352,8 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason) bool is_delegated_to_mst_top_mgr = false; enum dc_connection_type pre_link_type = link->type; + DC_LOGGER_INIT(link->ctx->logger); + is_local_sink_detect_success = detect_link_and_local_sink(link, reason); if (is_local_sink_detect_success && link->local_sink) @@ -1359,6 +1364,10 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason) link->dpcd_caps.is_mst_capable) is_delegated_to_mst_top_mgr = discover_dp_mst_topology(link, reason); + DC_LOG_DC("%s: link_index=%d is_local_sink_detect_success=%d pre_link_type=%d link_type=%d\n", __func__, + link->link_index, is_local_sink_detect_success, pre_link_type, link->type); + + if (is_local_sink_detect_success && pre_link_type == dc_connection_mst_branch && link->type != dc_connection_mst_branch) -- 2.39.2