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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E5E0C433F5 for ; Thu, 23 Dec 2021 11:57:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348057AbhLWL5D (ORCPT ); Thu, 23 Dec 2021 06:57:03 -0500 Received: from mga04.intel.com ([192.55.52.120]:62904 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236799AbhLWL5C (ORCPT ); Thu, 23 Dec 2021 06:57:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1640260622; x=1671796622; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=l7/Ec1k8g+Fuqc+4+s0zclAcRcBVVg9oTnf/81Ddgz8=; b=kYc3sNibFvI+YB1x1ukeZUl8W29DH/QdJbCOecGr02Q7EdxTHm7h0cU0 BE1KQp1pYgg9j2meS62cnO2f5Tio7fngBLC3i70N88bjc5QfA0+rwliIh qCBZ/yK24fOXIha9bpOzcSbJVLXZ5aFrGfblWJFvYjKZknfW65fxhwHMh 1i7kpK+p1PGkIgXPueCa3c4TCvk4FW3V5s4BpxduA7Qs2Dx4aNOnftnn9 2mtqOvk64GwwR4wSpZMM29vXG12c76onjergnNWfa0B0uNK+swa+mcbnI 6jdPJTgiodCPoYrdvgh4cDhKDe5PZYv6thsnW25kqljYE1vuDp6J2rN1s w==; X-IronPort-AV: E=McAfee;i="6200,9189,10206"; a="239568213" X-IronPort-AV: E=Sophos;i="5.88,229,1635231600"; d="scan'208";a="239568213" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Dec 2021 03:57:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,229,1635231600"; d="scan'208";a="607735683" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.147]) by FMSMGA003.fm.intel.com with SMTP; 23 Dec 2021 03:56:55 -0800 Received: by stinkbox (sSMTP sendmail emulation); Thu, 23 Dec 2021 13:56:55 +0200 Date: Thu, 23 Dec 2021 13:56:55 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: =?iso-8859-1?Q?Jos=E9_Exp=F3sito?= Cc: contact@emersion.fr, airlied@linux.ie, alexandre.torgue@foss.st.com, benjamin.gaignard@linaro.org, linux-stm32@st-md-mailman.stormreply.com, marex@denx.de, linux-imx@nxp.com, intel-gfx@lists.freedesktop.org, tzimmermann@suse.de, s.hauer@pengutronix.de, rodrigo.vivi@intel.com, kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, yannick.fertre@foss.st.com, linux-kernel@vger.kernel.org, philippe.cornu@foss.st.com, mcoquelin.stm32@gmail.com, dmitry.baryshkov@linaro.org, shawnguo@kernel.org Subject: Re: [PATCH v2 1/6] =?iso-8859-1?Q?drm=2Fpl?= =?iso-8859-1?Q?ane=3A_Make_format=5Fmod=5Fsupported_truly=A0optional?= Message-ID: References: <20211222090552.25972-1-jose.exposito89@gmail.com> <20211222090552.25972-2-jose.exposito89@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20211222090552.25972-2-jose.exposito89@gmail.com> X-Patchwork-Hint: comment Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 22, 2021 at 10:05:47AM +0100, José Expósito wrote: > The documentation for "drm_plane_funcs.format_mod_supported" reads: > > This *optional* hook is used for the DRM to determine if the given > format/modifier combination is valid for the plane. This allows the > DRM to generate the correct format bitmask (which formats apply to > which modifier), and to validate modifiers at atomic_check time. > > *If not present*, then any modifier in the plane's modifier > list is allowed with any of the plane's formats. > > However, where the function is not present, an invalid IN_FORMATS blob > property with modifiers but no formats is exposed to user-space. > > This breaks the latest Weston [1]. For testing purposes, I extracted the > affected code to a standalone program [2]. > > Make "create_in_format_blob" behave as documented. > > [1] https://gitlab.freedesktop.org/wayland/weston/-/blob/9.0/libweston/backend-drm/kms.c#L431 > [2] https://github.com/JoseExposito/drm-sandbox/blob/main/in_formats.c > > Signed-off-by: José Expósito > --- > drivers/gpu/drm/drm_plane.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c > index 82afb854141b..c1186b7215ee 100644 > --- a/drivers/gpu/drm/drm_plane.c > +++ b/drivers/gpu/drm/drm_plane.c > @@ -202,17 +202,13 @@ static int create_in_format_blob(struct drm_device *dev, struct drm_plane *plane > > memcpy(formats_ptr(blob_data), plane->format_types, formats_size); > > - /* If we can't determine support, just bail */ > - if (!plane->funcs->format_mod_supported) > - goto done; > - > mod = modifiers_ptr(blob_data); > for (i = 0; i < plane->modifier_count; i++) { > for (j = 0; j < plane->format_count; j++) { > - if (plane->funcs->format_mod_supported(plane, > + if (!plane->funcs->format_mod_supported || > + plane->funcs->format_mod_supported(plane, > plane->format_types[j], > plane->modifiers[i])) { So instead of skipping the whole loop you just skip doing anything inside the loop? Can't see how that achieves anything at all. https://patchwork.freedesktop.org/series/83018/ is what I had in mind earlier but no one reviewed it and the discussion veered off track IIRC. -- Ville Syrjälä Intel