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 4148CD44C4C for ; Fri, 16 Jan 2026 09:50:56 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EC66510E844; Fri, 16 Jan 2026 09:50:55 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Xl9fu/wE"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1738F10E840; Fri, 16 Jan 2026 09:50:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768557055; x=1800093055; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=rGnuuiGHTCK33n12B8lS8ws8dXFlcVUBexrpfI0qXH0=; b=Xl9fu/wEIoO1aKVADaMDKSC4u565sicDH8U8BVHtYY7HIkyXkXw8OpMN 8VfV+09p5u+mKjNJaQnfZpm86h5EdFSGuOh0U1ne86MkTNSAgYnTKUHAN 9Ldg94lUIQmmiLvtGbp8QrWFVXws9/WVSdKq8gxO8pL96jRXvvz64dDHd OtRBpRfJtc10+hqRj0NuaPIHl7AWuxEHfDjAH6gNop2QGNlqMbEMxKlB0 UAsf7N2KJZYzsxGooo7QPrAGjfRy7lO2JCYIZwiwmhrCyeag6xFYkJwGZ Vf+GEjdWUa5TH2pKwkGv8kcb6MI/h5+HfPK/515PfCANYCRLQJNtcl5Fv A==; X-CSE-ConnectionGUID: k7cif0KASyCXo7eiNpEpNQ== X-CSE-MsgGUID: ZYyRCbQaTTKMsoqXx4jw7w== X-IronPort-AV: E=McAfee;i="6800,10657,11672"; a="80987496" X-IronPort-AV: E=Sophos;i="6.21,230,1763452800"; d="scan'208";a="80987496" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jan 2026 01:50:54 -0800 X-CSE-ConnectionGUID: JX+nYLThTNGpaL+oGubYAA== X-CSE-MsgGUID: lnj2SeAwSX6+MEk3w6U9aA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,230,1763452800"; d="scan'208";a="235893561" Received: from ettammin-desk.ger.corp.intel.com (HELO localhost) ([10.245.246.205]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jan 2026 01:50:50 -0800 From: Jani Nikula To: Kaushlendra Kumar , rodrigo.vivi@intel.com, joonas.lahtinen@linux.intel.com, tursulin@ursulin.net, airlied@gmail.com, simona@ffwll.ch Cc: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Kaushlendra Kumar Subject: Re: [PATCH] drm/i915/crtc: Guard vblank wait when CRTC lookup fails In-Reply-To: <20260116062203.1650454-1-kaushlendra.kumar@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland References: <20260116062203.1650454-1-kaushlendra.kumar@intel.com> Date: Fri, 16 Jan 2026 11:50:46 +0200 Message-ID: <6f7ad8bd5d41e50176d98cfb658aaa7b77f63cd0@intel.com> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Fri, 16 Jan 2026, Kaushlendra Kumar wrote: > intel_crtc_for_pipe() may return NULL in teardown/error paths. > Add a NULL check in intel_wait_for_vblank_if_active() to avoid > dereferencing a missing CRTC and rare NULL deref panics. Do you have the backtrace? BR, Jani. > > Fixes: 92e9624ad946 ("drm/i915/crtc: un-inline some crtc functions and move to intel_crtc.[ch]") > Signed-off-by: Kaushlendra Kumar > --- > drivers/gpu/drm/i915/display/intel_crtc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c > index 9d2a23c96c61..9eb158737c1c 100644 > --- a/drivers/gpu/drm/i915/display/intel_crtc.c > +++ b/drivers/gpu/drm/i915/display/intel_crtc.c > @@ -74,7 +74,7 @@ void intel_wait_for_vblank_if_active(struct intel_display *display, > { > struct intel_crtc *crtc = intel_crtc_for_pipe(display, pipe); > > - if (crtc->active) > + if (crtc && crtc->active) > intel_crtc_wait_for_next_vblank(crtc); > } -- Jani Nikula, Intel