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 8938DD4920F for ; Mon, 18 Nov 2024 11:45:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E04BD10E49D; Mon, 18 Nov 2024 11:45:14 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="PRLKwEvE"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4A2E810E193; Mon, 18 Nov 2024 11:45:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1731930313; x=1763466313; h=from:to:subject:in-reply-to:references:date:message-id: mime-version; bh=WHnvn6U6QGYnQpC2tu2f7Zlp6UgrR3aNeDN12KB1cK8=; b=PRLKwEvE+tBZisk424JDOQGTYe0LpoKuUk4CR0jnV4VgdfXV5jeEjtwm EsEyCgHVeD1JuYsj8k5gxPd+gnO1EUH94mLa5Yn3BcYWdnLfQY0dFIZIy ZMPIf0u24dfh+iTmDQe1WLcb/W2cpw80SNdhm0Ns14Aiv3j3JYrBvhn5z DiCZjurhIPd/zxG02JI/GuWDPdIWa+t7aGQaQAUoYTHW3TeYt5PsnF7Mx SnpmioyeLKCIQAnUdUcN5xXEv9FC6oqGIdU0KCcxnYiyKQBTjIsVyTVQX 9RY3g7oc2BTn6y86UTwo0N0QDeRciAfLsir0GHpL0bC1rjSCxxc1k0ajh Q==; X-CSE-ConnectionGUID: WRmkZwueS66FHxFKnFbUzA== X-CSE-MsgGUID: hHgaGAVKQoqRudYz4yCmrA== X-IronPort-AV: E=McAfee;i="6700,10204,11259"; a="31287870" X-IronPort-AV: E=Sophos;i="6.12,164,1728975600"; d="scan'208";a="31287870" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Nov 2024 03:45:12 -0800 X-CSE-ConnectionGUID: 3i510Gq9THK7D8zmyyxKfQ== X-CSE-MsgGUID: 5ocyj2ktSSiEXH8KeG9M9w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,164,1728975600"; d="scan'208";a="89117551" Received: from jkrzyszt-mobl2.ger.corp.intel.com (HELO localhost) ([10.245.246.148]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Nov 2024 03:45:11 -0800 From: Jani Nikula To: Imre Deak , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH 1/4] drm/i915/dp_mst: Fix connector initialization in intel_dp_add_mst_connector() In-Reply-To: <20241115164159.1081675-1-imre.deak@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20241115164159.1081675-1-imre.deak@intel.com> Date: Mon, 18 Nov 2024 13:45:07 +0200 Message-ID: <87frno4vgc.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain 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" On Fri, 15 Nov 2024, Imre Deak wrote: > The connector initialization in intel_dp_add_mst_connector() depends on > the device pointer in connector to be valid, at least by connector > debug printing. The device pointer is initialized by drm_connector_init(), > however that function also exposes the connector to in-kernel users, > which can't be done before the connector is fully initialized. For now > make sure the device pointer is valid before it's used, until a > follow-up change moving this to DRM core. > > This issue was revealed by the commit in the Fixes: line below, before > which the above debug printing checked and handled a NULL device pointer > gracefully in DRM core. > > Cc: Jani Nikula > Fixes: 529798bd786a ("drm/i915/mst: convert to struct intel_display") > Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12799 > Signed-off-by: Imre Deak I think you should send this patch alone to intel-gfx and intel-xe to address the regression. The others can follow later, and likely be merged via drm-misc. I have some comments about them, but I don't want to block fixing the issue. BR, Jani. > --- > drivers/gpu/drm/i915/display/intel_dp_mst.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c > index df7edcfe885b6..f058360a26413 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c > @@ -1727,6 +1727,16 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo > > intel_dp_init_modeset_retry_work(intel_connector); > > + /* > + * TODO: The following drm_connector specific initialization belongs > + * to DRM core, however it happens atm too late in > + * drm_connector_init(). That function will also expose the connector > + * to in-kernel users, so it can't be called until the connector is > + * sufficiently initialized; init the device pointer used by the > + * following DSC setup, until a fix moving this to DRM core. > + */ > + intel_connector->base.dev = mgr->dev; > + > intel_connector->dp.dsc_decompression_aux = drm_dp_mst_dsc_aux_for_port(port); > intel_dp_mst_read_decompression_port_dsc_caps(intel_dp, intel_connector); > intel_connector->dp.dsc_hblank_expansion_quirk = -- Jani Nikula, Intel