From patchwork Fri Feb 9 16:03:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Imre Deak X-Patchwork-Id: 13551519 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 95048C48297 for ; Fri, 9 Feb 2024 16:03:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E503710F6AC; Fri, 9 Feb 2024 16:03:01 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="mYdfSGht"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) by gabe.freedesktop.org (Postfix) with ESMTPS id DA69810F6AC for ; Fri, 9 Feb 2024 16:03:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707494581; x=1739030581; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OawYlz/f7E+Zc/KQeN+755bM5Mkw/7wkmBzxM/vuUKw=; b=mYdfSGhtLTGjkMR59+bTFyLRCkarkKxtg4TKE3rGTkIiATu3iZwM9JOp OgNp+Hkn5P5rTN5o3lLp+t2/ySKZDTWWpsJdCBhx+qBkkMs1gvg7tjHow dnKz919vk6wR7IupvmteCl0HtyUlVWjql3AH2dWOtgmdrhzapefzwStvb 5vg05DJzgFd8O2m3kpQ2901u02i8QMvkhnw9pISIWY77trcLnjlQF7CId ZyzRUDKv25/OSU4Tr9VWRqAbfjSgsBs6lcut12eKPJwm0gAEB1jX/g04j RPEg/LHug0VLrU9804leTkyAA3/I4yosovBWwB9LINnWApCoQoOSyCdB1 A==; X-IronPort-AV: E=McAfee;i="6600,9927,10979"; a="5246821" X-IronPort-AV: E=Sophos;i="6.05,257,1701158400"; d="scan'208";a="5246821" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Feb 2024 08:03:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,257,1701158400"; d="scan'208";a="2006506" Received: from unknown (HELO ideak-desk.fi.intel.com) ([10.237.66.155]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Feb 2024 08:03:00 -0800 From: Imre Deak To: intel-gfx@lists.freedesktop.org Cc: =?utf-8?q?Jouni_H=C3=B6gander?= Subject: [PATCH v3 2/2] drm/i915: Prevent HW access during init from connector get_modes hooks Date: Fri, 9 Feb 2024 18:03:16 +0200 Message-Id: <20240209160316.2160747-2-imre.deak@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240209160316.2160747-1-imre.deak@intel.com> References: <20240209160316.2160747-1-imre.deak@intel.com> MIME-Version: 1.0 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Prevent accessing the HW from the get_modes hooks of connectors deriving the mode list from the display's EDID. drm_edid_connector_add_modes() will return the mode list based on the EDID which was cached during a previous detection/get_modes call. This also fixes the NULL deref problem (10085) which was introduced/revealed by commit bab87ef4db9a ("drm/i915: Disable hotplug detection handlers during driver init/shutdown") After the above change MST connectors will not change state during driver init/shutdown; thus some of these connectors with no I2C/DDC adapter registered for them (since the given MST port has no sink connected) may stay then in the 'unknown' connector status. The get_modes() hook should not try to use the I2C/DDC adapter in this state (which would lead to the above NULL deref) which this patch ensures. v2: - Remove the redundant check from intel_crt_ddc_get_modes(). - Rebase on latest drm-tip. - Add Fixes: line / related commit notes. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10085 Fixes: bab87ef4db9a ("drm/i915: Disable hotplug detection handlers during driver init/shutdown") Signed-off-by: Imre Deak Reviewed-by: Jouni Högander Link: https://patchwork.freedesktop.org/patch/msgid/20240206153910.1758057-3-imre.deak@intel.com --- drivers/gpu/drm/i915/display/intel_crt.c | 3 +++ drivers/gpu/drm/i915/display/intel_dp_mst.c | 4 ++++ drivers/gpu/drm/i915/display/intel_dvo.c | 5 +++++ drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++ 4 files changed, 16 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_crt.c b/drivers/gpu/drm/i915/display/intel_crt.c index b9733a73e21d4..93479db0f89f6 100644 --- a/drivers/gpu/drm/i915/display/intel_crt.c +++ b/drivers/gpu/drm/i915/display/intel_crt.c @@ -933,6 +933,9 @@ static int intel_crt_get_modes(struct drm_connector *connector) struct i2c_adapter *ddc; int ret; + if (!intel_display_driver_check_access(dev_priv)) + return drm_edid_connector_add_modes(connector); + wakeref = intel_display_power_get(dev_priv, intel_encoder->power_domain); diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 5fa25a5a36b55..5307ddd4edcf5 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -1197,6 +1197,7 @@ static bool intel_dp_mst_initial_fastset_check(struct intel_encoder *encoder, static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector) { struct intel_connector *intel_connector = to_intel_connector(connector); + struct drm_i915_private *i915 = to_i915(intel_connector->base.dev); struct intel_dp *intel_dp = intel_connector->mst_port; const struct drm_edid *drm_edid; int ret; @@ -1204,6 +1205,9 @@ static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector) if (drm_connector_is_unregistered(connector)) return intel_connector_update_modes(connector, NULL); + if (!intel_display_driver_check_access(i915)) + return drm_edid_connector_add_modes(connector); + drm_edid = drm_dp_mst_edid_read(connector, &intel_dp->mst_mgr, intel_connector->port); ret = intel_connector_update_modes(connector, drm_edid); diff --git a/drivers/gpu/drm/i915/display/intel_dvo.c b/drivers/gpu/drm/i915/display/intel_dvo.c index 8ca9ae4798a89..c076da75b066e 100644 --- a/drivers/gpu/drm/i915/display/intel_dvo.c +++ b/drivers/gpu/drm/i915/display/intel_dvo.c @@ -30,6 +30,7 @@ #include #include +#include #include "i915_drv.h" #include "i915_reg.h" @@ -338,8 +339,12 @@ intel_dvo_detect(struct drm_connector *_connector, bool force) static int intel_dvo_get_modes(struct drm_connector *_connector) { struct intel_connector *connector = to_intel_connector(_connector); + struct drm_i915_private *i915 = to_i915(connector->base.dev); int num_modes; + if (!intel_display_driver_check_access(i915)) + return drm_edid_connector_add_modes(&connector->base); + /* * We should probably have an i2c driver get_modes function for those * devices which will have a fixed set of modes determined by the chip diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c b/drivers/gpu/drm/i915/display/intel_sdvo.c index c67605059aa3e..825638702ac1b 100644 --- a/drivers/gpu/drm/i915/display/intel_sdvo.c +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c @@ -2202,12 +2202,16 @@ intel_sdvo_detect(struct drm_connector *connector, bool force) static int intel_sdvo_get_ddc_modes(struct drm_connector *connector) { + struct drm_i915_private *i915 = to_i915(connector->dev); int num_modes = 0; const struct drm_edid *drm_edid; drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s]\n", connector->base.id, connector->name); + if (!intel_display_driver_check_access(i915)) + return drm_edid_connector_add_modes(connector); + /* set the bus switch and get the modes */ drm_edid = intel_sdvo_get_edid(connector);