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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 8AA32ECAAD5 for ; Mon, 29 Aug 2022 13:48:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 11E5410F2A8; Mon, 29 Aug 2022 13:48:31 +0000 (UTC) Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by gabe.freedesktop.org (Postfix) with ESMTPS id D65E410F2A4 for ; Mon, 29 Aug 2022 13:48:18 +0000 (UTC) Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id 7528E32004CE; Mon, 29 Aug 2022 09:48:17 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Mon, 29 Aug 2022 09:48:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cerno.tech; h=cc :cc:content-transfer-encoding:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm3; t=1661780896; x=1661867296; bh=k1 AFbr1RpW7/E4mqaSBi+oqOyDuhsIcZHMpv6rQZqZU=; b=Sab88IHGJ6CYIc9EYB J0zJQwYQTcHHuWFoHDs8IDUkFXP+5euqptiWHYO9VeimIlZD7p+awbwWGVfxccYJ r84lXO1/Dt6wLa9qgHS4dyRj4eg1abDnDUIH5YkqcN3fqGd6vNJyIZhYsE2/0FvQ LPALxvYxmqyiUysED/3iVzwJwCj4jocyElIdYwGfqnlr3G7B4ukV3wLnmCSQcd/A rGO3qmq3di4I4NxKsEvEk2EDo3RfIU31BeImTnr4RHv2MepjfoZbAaA5w1sOTLjY YATJTULzfL9YedwdQdu6ysrMBjlMkc0BSP4HAKtoJkphFAgW5mIKr/vIjoUJ/bNk TH3Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; t=1661780896; x=1661867296; bh=k1AFbr1RpW7/E 4mqaSBi+oqOyDuhsIcZHMpv6rQZqZU=; b=SBZhti2H1991DfM9X6yv9Qt5YQKlB PD2IS8UZa0+gCJ9gQi6uMXSi/MKkGuQiH1C0+Xpu389aLRKZUMU8bX68XTbXvqdD oBNj/qwOohQuxcXg30yAcodFBV0rXigKPBFPcVQ84aHlTtm9m/AZGsTS3QnnZfaE AWEsrlUfj+JaffUhgLKRrQMhDsXBm9kkIT3hHFrXbsP7tsmCZsYxdenoz0AZ+1r8 Wzct3gjojuJFD8Glc8ltoDAOv6Fvg/K7AX+EMmbiOWqTWkDaYFgQEaA2129Lp9AS D2EG6KSDwg10JDZhOk9GMsmKZYdmApzky0d7ibNWLSn0a1SxUflwXRcaw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvfedrvdekuddgjedtucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvvefufffkofgjfhgggfestdekredtredttdenucfhrhhomhepofgrgihi mhgvucftihhprghrugcuoehmrgigihhmvgestggvrhhnohdrthgvtghhqeenucggtffrrg htthgvrhhnpeelkeefteduhfekjeeihfetudfguedvveekkeetteekhfekhfdtlefgfedu vdejhfenucevlhhushhtvghrufhiiigvpeefnecurfgrrhgrmhepmhgrihhlfhhrohhmpe hmrgigihhmvgestggvrhhnohdrthgvtghh X-ME-Proxy: Feedback-ID: i8771445c:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 29 Aug 2022 09:48:16 -0400 (EDT) From: Maxime Ripard To: Maarten Lankhorst , Thomas Zimmermann , Maxime Ripard , Daniel Vetter , David Airlie Subject: [PATCH v4 7/8] drm/vc4: hdmi: Reset link on hotplug Date: Mon, 29 Aug 2022 15:47:30 +0200 Message-Id: <20220829134731.213478-8-maxime@cerno.tech> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220829134731.213478-1-maxime@cerno.tech> References: <20220829134731.213478-1-maxime@cerno.tech> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: , Cc: Dom Cobley , Tim Gover , Dave Stevenson , dri-devel@lists.freedesktop.org, Phil Elwell Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" During a hotplug cycle (such as a TV going out of suspend, or when the cable is disconnected and reconnected), the expectation is that the same state used before the disconnection is reused until the next commit. However, the HDMI scrambling requires that some flags are set in the monitor, and those flags are very likely to be reset when the cable has been disconnected. This will thus result in a blank display, even if the display pipeline configuration hasn't been modified or is in the exact same state. The solution we've had so far is to enable the scrambling-related bits again on reconnection, but the HDMI 2.0 specification (Section 6.1.3.1 - Scrambling Control) requires that the scrambling enable bit is set before sending any scrambled video signal. Using that solution thus breaks that expectation. The solution used by i915 is to do a full modeset on the connector so that we disable the video signal, enable the scrambling bit, and enable the video signal again. As such, we took that code and plugged it into vc4. It probably could have been turned into an helper, but it proved to be difficult for several reasons: * i915 has fairly different structures than simpler KMS drivers such as vc4, so doing some code that works with both proved to be difficult; * Other simpler drivers could reuse some of it (tegra, dw-hdmi), but it would still require to move some parameters currently stored in private structure that are needed to compute whether the scrambling is needed or not, and then inform the driver that it needs to be enabled. Some of those parameters are already in core structures (drm_display_mode, drm_display_info, bpc), but the output format isnt't. Adding it is fairly challenging since unlike the TMDS char rate or mode, there's no consensus on what format to pick in drivers, so it's not possible to write some generic code that can depend on it. For these reasons, we chose to duplicate the code for now, until someone else really needs it as well, in which case we will be able to convert it into a generic helper. Signed-off-by: Maxime Ripard --- drivers/gpu/drm/vc4/vc4_hdmi.c | 104 ++++++++++++++++++++++++++++++++- 1 file changed, 101 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index a510da7462fd..1b3131947a5b 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -288,9 +288,103 @@ static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi) static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi) {} #endif -static void vc4_hdmi_enable_scrambling(struct drm_encoder *encoder); +static int reset_pipe(struct drm_crtc *crtc, + struct drm_modeset_acquire_ctx *ctx) +{ + struct drm_atomic_state *state; + struct drm_crtc_state *crtc_state; + int ret; + + state = drm_atomic_state_alloc(crtc->dev); + if (!state) + return -ENOMEM; + + state->acquire_ctx = ctx; + + crtc_state = drm_atomic_get_crtc_state(state, crtc); + if (IS_ERR(crtc_state)) { + ret = PTR_ERR(crtc_state); + goto out; + } + + crtc_state->connectors_changed = true; + + ret = drm_atomic_commit(state); +out: + drm_atomic_state_put(state); + + return ret; +} + +static int vc4_hdmi_reset_link(struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx) +{ + struct drm_device *drm = connector->dev; + struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector); + struct drm_encoder *encoder = &vc4_hdmi->encoder.base; + struct drm_connector_state *conn_state; + struct drm_crtc_state *crtc_state; + struct drm_crtc *crtc; + bool scrambling_needed; + u8 config; + int ret; + + if (!connector) + return 0; + + ret = drm_modeset_lock(&drm->mode_config.connection_mutex, ctx); + if (ret) + return ret; + + conn_state = connector->state; + crtc = conn_state->crtc; + if (!crtc) + return 0; + + ret = drm_modeset_lock(&crtc->mutex, ctx); + if (ret) + return ret; + + crtc_state = crtc->state; + if (!crtc_state->active) + return 0; + + if (!vc4_hdmi_supports_scrambling(encoder)) + return 0; + + scrambling_needed = vc4_hdmi_mode_needs_scrambling(&vc4_hdmi->saved_adjusted_mode, + vc4_hdmi->output_bpc, + vc4_hdmi->output_format); + if (!scrambling_needed) + return 0; + + if (conn_state->commit && + !try_wait_for_completion(&conn_state->commit->hw_done)) + return 0; + + ret = drm_scdc_readb(connector->ddc, SCDC_TMDS_CONFIG, &config); + if (ret < 0) { + drm_err(drm, "Failed to read TMDS config: %d\n", ret); + return 0; + } + + if (!!(config & SCDC_SCRAMBLING_ENABLE) == scrambling_needed) + return 0; + + /* + * HDMI 2.0 says that one should not send scrambled data + * prior to configuring the sink scrambling, and that + * TMDS clock/data transmission should be suspended when + * changing the TMDS clock rate in the sink. So let's + * just do a full modeset here, even though some sinks + * would be perfectly happy if were to just reconfigure + * the SCDC settings on the fly. + */ + return reset_pipe(crtc, ctx); +} static void vc4_hdmi_handle_hotplug(struct vc4_hdmi *vc4_hdmi, + struct drm_modeset_acquire_ctx *ctx, enum drm_connector_status status) { struct drm_connector *connector = &vc4_hdmi->connector; @@ -303,6 +397,10 @@ static void vc4_hdmi_handle_hotplug(struct vc4_hdmi *vc4_hdmi, * .adap_enable, which leads to that funtion being called with * our mutex held. * + * A similar situation occurs with + * drm_atomic_helper_connector_hdmi_reset_link() that will call + * into our KMS hooks if the scrambling was enabled. + * * Concurrency isn't an issue at the moment since we don't share * any state with any of the other frameworks so we can ignore * the lock for now. @@ -323,7 +421,7 @@ static void vc4_hdmi_handle_hotplug(struct vc4_hdmi *vc4_hdmi, cec_s_phys_addr_from_edid(vc4_hdmi->cec_adap, edid); kfree(edid); - vc4_hdmi_enable_scrambling(&vc4_hdmi->encoder.base.base); + vc4_hdmi_reset_link(connector, ctx); } static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector, @@ -355,7 +453,7 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector, status = connector_status_connected; } - vc4_hdmi_handle_hotplug(vc4_hdmi, status); + vc4_hdmi_handle_hotplug(vc4_hdmi, ctx, status); pm_runtime_put(&vc4_hdmi->pdev->dev); return status; -- 2.37.1