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 78E1BCA6C9D for ; Tue, 27 Jan 2026 08:44:26 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ED69E10E03F; Tue, 27 Jan 2026 08:44:25 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="dv8hcOf/"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id C87E010E03F for ; Tue, 27 Jan 2026 08:44:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769503464; x=1801039464; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=Vsbrd1Wgn44Nim3sZsaERig81bKQT7LTOWibZ6pODzw=; b=dv8hcOf/zXl1eI3S6WwHP/Awmk7wu2drwuqBmoFQqcYvLm/GSKBw5z+H 0PTYVh7YFGONrj8DtRJjO2pdyD1FDSsSipo6juR52QcjhaaNbtV6Xn2qu BUlHaVxTBb4R41VuV8UpQDIEwTLyUUnO4wBmL+7bIV5DPyl2wlGhET1Uw GzC3A6Fr9JoJinVWiRFl5WY/rXEa8dqMq7B0qrwRGHE9j4F/xKHqoTIMr uydXQHS4JGcInJzqUOwQtHMBlFDDLL1vVlMLZZyRwEvv+oKahf/HFSGhu Qboj1fLeCFR+86zM+hNkr6D0c784lud5z0rGrDloit7TL/ozwLej3gsNG Q==; X-CSE-ConnectionGUID: BovgUClvRZez38234ls0UQ== X-CSE-MsgGUID: Xee5dt13Sy+nSmtbvhuKlQ== X-IronPort-AV: E=McAfee;i="6800,10657,11683"; a="70751246" X-IronPort-AV: E=Sophos;i="6.21,256,1763452800"; d="scan'208";a="70751246" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jan 2026 00:44:22 -0800 X-CSE-ConnectionGUID: e/9YNKAGS1SKwfoF80BUnw== X-CSE-MsgGUID: u8/kt4XzTD2GjWfQed/F8w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,256,1763452800"; d="scan'208";a="207719950" Received: from mjarzebo-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.246.148]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jan 2026 00:44:20 -0800 From: Jani Nikula To: Jonathan Cavitt , intel-gfx@lists.freedesktop.org Cc: saurabhg.gupta@intel.com, alex.zuo@intel.com, jonathan.cavitt@intel.com Subject: Re: [PATCH] drm/i915/display: Assert valid cpu_transcoder In-Reply-To: <20260126225702.66437-2-jonathan.cavitt@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland References: <20260126225702.66437-2-jonathan.cavitt@intel.com> Date: Tue, 27 Jan 2026 10:44:17 +0200 Message-ID: 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 Mon, 26 Jan 2026, Jonathan Cavitt wrote: > Static analysis issue: > > Bit operations are being performed using bit offsets computed from > cpu_transcoder values, which may (albeit unlikely) be -1. Assert this > is not the case when relevant. > > Signed-off-by: Jonathan Cavitt > --- > drivers/gpu/drm/i915/display/intel_ddi.c | 8 +++++++- > drivers/gpu/drm/i915/display/intel_display.c | 5 +++++ > drivers/gpu/drm/i915/display/intel_dp.c | 3 +++ > drivers/gpu/drm/i915/display/intel_dp_mst.c | 3 +++ > 4 files changed, 18 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c > index d8739e2bb004..ec947c415e5f 100644 > --- a/drivers/gpu/drm/i915/display/intel_ddi.c > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c > @@ -3876,7 +3876,8 @@ static void intel_ddi_set_idle_link_train(struct intel_dp *intel_dp, > static bool intel_ddi_is_audio_enabled(struct intel_display *display, > enum transcoder cpu_transcoder) > { > - if (cpu_transcoder == TRANSCODER_EDP) > + if (cpu_transcoder == TRANSCODER_EDP || > + drm_WARN_ON(display->drm, cpu_transcoder == INVALID_TRANSCODER)) > return false; > > if (!intel_display_power_is_enabled(display, POWER_DOMAIN_AUDIO_MMIO)) > @@ -4611,6 +4612,8 @@ intel_ddi_port_sync_transcoders(const struct intel_crtc_state *ref_crtc_state, > if (!crtcs_port_sync_compatible(ref_crtc_state, > crtc_state)) > continue; > + if (drm_WARN_ON(display->drm, crtc_state->cpu_transcoder == INVALID_TRANSCODER)) > + continue; > transcoders |= BIT(crtc_state->cpu_transcoder); > } > > @@ -4649,6 +4652,9 @@ static int intel_ddi_compute_config_late(struct intel_encoder *encoder, > else > crtc_state->master_transcoder = ffs(port_sync_transcoders) - 1; > > + if (drm_WARN_ON(display->drm, crtc_state->cpu_transcoder == INVALID_TRANSCODER)) > + return -EINVAL; > + > if (crtc_state->master_transcoder == crtc_state->cpu_transcoder) { > crtc_state->master_transcoder = INVALID_TRANSCODER; > crtc_state->sync_mode_slaves_mask = > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c > index 7491e00e3858..c9d50240d813 100644 > --- a/drivers/gpu/drm/i915/display/intel_display.c > +++ b/drivers/gpu/drm/i915/display/intel_display.c > @@ -5855,9 +5855,14 @@ static bool intel_cpu_transcoders_need_modeset(struct intel_atomic_state *state, > { > const struct intel_crtc_state *new_crtc_state; > struct intel_crtc *crtc; > + struct drm_device *drm; > int i; > > + drm = to_intel_display(state)->drm; Please don't add struct drm_device local variables in display code. Add display, and use display->drm instead. BR, Jani. > + > for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) { > + if (drm_WARN_ON(drm, new_crtc_state->cpu_transcoder == INVALID_TRANSCODER)) > + continue; > if (new_crtc_state->hw.enable && > transcoders & BIT(new_crtc_state->cpu_transcoder) && > intel_crtc_needs_modeset(new_crtc_state)) > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > index 79fd3b8d8b25..402b22423ff2 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -6412,6 +6412,9 @@ static int intel_modeset_affected_transcoders(struct intel_atomic_state *state, > if (!crtc_state->hw.enable) > continue; > > + if (drm_WARN_ON(display->drm, crtc_state->cpu_transcoder == INVALID_TRANSCODER)) > + continue; > + > if (!(transcoders & BIT(crtc_state->cpu_transcoder))) > continue; > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c > index 24f8e60df9ac..f6690130d1cb 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c > @@ -741,6 +741,9 @@ intel_dp_mst_transcoder_mask(struct intel_atomic_state *state, > if (!crtc_state->hw.active) > continue; > > + if (drm_WARN_ON(display->drm, crtc_state->cpu_transcoder == INVALID_TRANSCODER)) > + continue; > + > transcoders |= BIT(crtc_state->cpu_transcoder); > } -- Jani Nikula, Intel