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 71E9CE77182 for ; Wed, 11 Dec 2024 14:56:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 33DF310EB77; Wed, 11 Dec 2024 14:56:53 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="Hqna+FOR"; dkim-atps=neutral Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by gabe.freedesktop.org (Postfix) with ESMTPS id E85B210E1C8; Wed, 11 Dec 2024 14:56:51 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id AC0F0A42339; Wed, 11 Dec 2024 14:54:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5AA8C4CED4; Wed, 11 Dec 2024 14:56:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733929010; bh=OREpjiujqd4SpEZvxAc06dWhF5wUZtZuOpJQ2zmJ8fo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Hqna+FORRl5s+hoVNX1PHcAkrXrpDQAzfv3NlWXzozI+wZiDZ9WBguGPAcyZkoVQ5 0CtxxAowC8RaEdJMSlzLkrp3IUwDW3JMLdjLrSs41emwNl+Y6yzhrDM546MppyN+Yl nnw8RlLR7bspvO+J+GDQsGPpmPxzMB7JWfnwOtasrvSfgVWx91ff+nLOU0TIihH8wJ nLGG/wQEzgYZ2vliQ3sVwcAHKGmrmcW356DKkU4Spduc1T7ehj0yZm5P5bkqDMHsdq RwyjSvRidsZIryVplu/6/gBL92iRjHH0Jt5G7eu/eUprRLUrfMYIZXTKJePQiOOk24 TPuRWRdoA1Dag== Received: from johan by xi.lan with local (Exim 4.97.1) (envelope-from ) id 1tLO8z-000000003BN-11Dy; Wed, 11 Dec 2024 15:56:53 +0100 Date: Wed, 11 Dec 2024 15:56:53 +0100 From: Johan Hovold To: Abel Vesa Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Karol Herbst , Lyude Paul , Danilo Krummrich , Jani Nikula , Rodrigo Vivi , Joonas Lahtinen , Tvrtko Ursulin , Rob Clark , Abhinav Kumar , Dmitry Baryshkov , Sean Paul , Marijn Suijten , Bjorn Andersson , Konrad Dybcio , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org Subject: Re: [PATCH v2 4/4] drm/msm/dp: Add support for LTTPR handling Message-ID: References: <20241211-drm-dp-msm-add-lttpr-transparent-mode-set-v2-0-d5906ed38b28@linaro.org> <20241211-drm-dp-msm-add-lttpr-transparent-mode-set-v2-4-d5906ed38b28@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241211-drm-dp-msm-add-lttpr-transparent-mode-set-v2-4-d5906ed38b28@linaro.org> 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 Wed, Dec 11, 2024 at 03:04:15PM +0200, Abel Vesa wrote: > +static void msm_dp_display_lttpr_init(struct msm_dp_display_private *dp) > +{ > + int lttpr_count; > + > + if (drm_dp_read_lttpr_common_caps(dp->aux, dp->panel->dpcd, > + dp->lttpr_caps)) > + return; > + > + lttpr_count = drm_dp_lttpr_count(dp->lttpr_caps); I was gonna say shouldn't you handle errors here, but that explains the non-negative check I commented on the first patch in the series. This looks error prone, but I think you should at least update the kernel doc comment to drm_dp_lttpr_init() in the first patch so that it's clear that you pass in the number of LTTPRs *or* an errno. > + > + drm_dp_lttpr_init(dp->aux, lttpr_count); > +} > + > static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp) > { > struct drm_connector *connector = dp->msm_dp_display.connector; > const struct drm_display_info *info = &connector->display_info; > int rc = 0; > > + msm_dp_display_lttpr_init(dp); It looks like you ignore errors on purpose so I guess that's fine. > + > rc = msm_dp_panel_read_sink_caps(dp->panel, connector); > if (rc) > goto end; Either way, this is needed for external display on my x1e80100 machines, while not breaking the X13s: Tested-by: Johan Hovold Johan