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 25072CEBF9C for ; Fri, 27 Sep 2024 11:58:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C7F5B10E339; Fri, 27 Sep 2024 11:58:04 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="IrF+K5ZB"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8A7CF10E335; Fri, 27 Sep 2024 11:58:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1727438283; x=1758974283; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=cE3DSOxu2KhQ4VUt6KjdR+DUz74JcXwEdHUB+LUYDoU=; b=IrF+K5ZBehI0uaI9hRt/L+KdXLdONRC8fYq3KVihSDcLLZ2V+Ajm8Cf7 Y09y4ibb0x0PE5bB8sz263entVfYhrDtN3xgyCkCpAbSd8ug7eEFV/8rg ALXQyV3vMcA9Mzt0+djeKJ8l6F2O3Wy0ach08KdtFAl7Sx7ANMZVRjcEI LgHnkYD82wxSQnEdATcCFtl38wKvBXvreuNemBjk6RuoG9CPY9ka+nBO7 jObImmIHROSOdafWcWjI1Vh8xDiZginTtvUy8uitw7lb65p6Ptz/c9EHR zk/WwwGbdO4g8FelNF7c9wujQ46sIpv3JgiUPM2s+K2hYkx1Uulp6Z7Hd A==; X-CSE-ConnectionGUID: Hi/ZWUz8QkC2MHzyt+OQeg== X-CSE-MsgGUID: nMt6g4RUSP6jZDgh0W7gRw== X-IronPort-AV: E=McAfee;i="6700,10204,11207"; a="30289418" X-IronPort-AV: E=Sophos;i="6.11,158,1725346800"; d="scan'208";a="30289418" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Sep 2024 04:58:03 -0700 X-CSE-ConnectionGUID: fOl91vxBR5Cr1bV1f6e8BA== X-CSE-MsgGUID: 5VSTsa3zTTu7LE+v2lKtJw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,158,1725346800"; d="scan'208";a="72688311" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.74]) by fmviesa008.fm.intel.com with SMTP; 27 Sep 2024 04:57:47 -0700 Received: by stinkbox (sSMTP sendmail emulation); Fri, 27 Sep 2024 14:57:46 +0300 Date: Fri, 27 Sep 2024 14:57:46 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Jani Nikula Cc: Alessandro Zanni , rodrigo.vivi@intel.com, joonas.lahtinen@linux.intel.com, tursulin@ursulin.net, airlied@gmail.com, simona@ffwll.ch, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, anupnewsmail@gmail.com Subject: Re: [PATCH] gpu: drm: i915: display: Avoid null values intel_plane_atomic_check_with_state Message-ID: References: <20240927000146.50830-1-alessandro.zanni87@gmail.com> <87tte1zewf.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87tte1zewf.fsf@intel.com> X-Patchwork-Hint: comment 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, Sep 27, 2024 at 11:20:32AM +0300, Jani Nikula wrote: > On Fri, 27 Sep 2024, Alessandro Zanni wrote: > > This fix solves multiple Smatch errors: > > > > drivers/gpu/drm/i915/display/intel_atomic_plane.c:660 > > intel_plane_atomic_check_with_state() error: > > we previously assumed 'fb' could be null (see line 648) > > > > drivers/gpu/drm/i915/display/intel_atomic_plane.c:664 > > intel_plane_atomic_check_with_state() > > error: we previously assumed 'fb' could be null (see line 659) > > > > drivers/gpu/drm/i915/display/intel_atomic_plane.c:671 > > intel_plane_atomic_check_with_state() > > error: we previously assumed 'fb' could be null (see line 663) > > > > We should check first if fb is not null before to access its properties. > > new_plane_state->uapi.visible && !fb should not be possible, but it's > probably too hard for smatch to figure out. It's not exactly trivial for > humans to figure out either. > > I'm thinking something like below to help both. > > Ville, thoughts? > > > BR, > Jani. > > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c > index 3505a5b52eb9..d9da47aed55d 100644 > --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c > +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c > @@ -629,6 +629,9 @@ int intel_plane_atomic_check_with_state(const struct intel_crtc_state *old_crtc_ > if (ret) > return ret; > > + if (drm_WARN_ON(display->drm, new_plane_state->uapi.visible && !fb)) > + return -EINVAL; > + We have probably 100 places that would need this. So it's going to be extremely ugly. One approach I could maybe tolerate is something like intel_plane_is_visible(plane_state) { if (drm_WARN_ON(visible && !fb)) return false; return plane_state->visible; } + s/plane_state->visible/intel_plane_is_visible(plane_state)/ But is that going to help these obtuse tools? > if (fb) > new_crtc_state->enabled_planes |= BIT(plane->id); > > > > > > > Signed-off-by: Alessandro Zanni > > --- > > drivers/gpu/drm/i915/display/intel_atomic_plane.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c > > index e979786aa5cf..1606f79b39e6 100644 > > --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c > > +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c > > @@ -656,18 +656,18 @@ int intel_plane_atomic_check_with_state(const struct intel_crtc_state *old_crtc_ > > intel_plane_is_scaled(new_plane_state)) > > new_crtc_state->scaled_planes |= BIT(plane->id); > > > > - if (new_plane_state->uapi.visible && > > + if (new_plane_state->uapi.visible && fb && > > intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier)) > > new_crtc_state->nv12_planes |= BIT(plane->id); > > > > - if (new_plane_state->uapi.visible && > > + if (new_plane_state->uapi.visible && fb && > > fb->format->format == DRM_FORMAT_C8) > > new_crtc_state->c8_planes |= BIT(plane->id); > > > > if (new_plane_state->uapi.visible || old_plane_state->uapi.visible) > > new_crtc_state->update_planes |= BIT(plane->id); > > > > - if (new_plane_state->uapi.visible && > > + if (new_plane_state->uapi.visible && fb && > > intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier)) { > > new_crtc_state->data_rate_y[plane->id] = > > intel_plane_data_rate(new_crtc_state, new_plane_state, 0); > > -- > Jani Nikula, Intel -- Ville Syrjälä Intel