From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B1626132114 for ; Wed, 28 Aug 2024 08:31:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724833888; cv=none; b=WQC1MEHVYqXw0cc9tqY5Oru+rV9jWHAporGjT9cTmYdTxNIMsywlo4ZgTMTOIxoIUNM4DPkBuuyo2XFvqEvEpyCaV9HDmw20tg3zmS/t7WhE0H+xEH6Og77i/5XdOZpj0GtrCR10zI5xK1U7q/Ou+yH8dTGbLANloUjpxKbZKJ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724833888; c=relaxed/simple; bh=xJuZ+EJ94pLSsNkzA+mfLjJFjy+ge3Om+5ox8Q/Z4rY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=FneCcnk/N7Y5VduEDZ+GB7QLTJYF0uff0yyMf4mpypFroSZ9rp3ylBtjhcfB+l/yrg5vZHGzDRYf1iLxWWKVpbaiizLNPhx/HiyQnKYVOv5ftaDV41/9cnRDAwH9kQkWftKzzDgGLd9WM/2/mRwCcnzMGhrmAygOAjuUCVBtZ6Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=G723RKVF; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="G723RKVF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1724833886; x=1756369886; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=xJuZ+EJ94pLSsNkzA+mfLjJFjy+ge3Om+5ox8Q/Z4rY=; b=G723RKVFyp8582U4rvhMiYyuViWjjyvbLg1888pOzO8YWUcQGbw+sHFB wcEkIMaNz5C3U0OhuDdHwjWuYBrBRXR+ipwz5Nunfvp9v3bLHXivCIcpK xHtsiw4YlqU/MJFazjt4J/F2i9b1/kxNcQRwqlvRJOqqkKH3IROUThAtF Uh4kFBt9TpZzLz36HuddZczS8p8rA2RFrA9uG65T+FhoaAokCVHYoMuCG FR85Q0wf71dz/FlLD7NzUJ0KJZ1VYz7PFfKJWO2VMhtsT08ScNgO6OT6Y 7NOBQJU6KQhCeMVLkO0tgbssKb9ESr//Yrx3bn4LnBdYfDnK65fHVQBI+ A==; X-CSE-ConnectionGUID: vA0dpbi0QCWOTW/FrUXqKA== X-CSE-MsgGUID: trowtpwlTLyaoKqW+sblcQ== X-IronPort-AV: E=McAfee;i="6700,10204,11177"; a="13255674" X-IronPort-AV: E=Sophos;i="6.10,182,1719903600"; d="scan'208";a="13255674" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Aug 2024 01:31:24 -0700 X-CSE-ConnectionGUID: eR2uKhlqSY6k0yuMgG2gSg== X-CSE-MsgGUID: CKK6zCmsTDaHJ11r4Su9vA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,182,1719903600"; d="scan'208";a="67830578" Received: from fdefranc-mobl3.ger.corp.intel.com (HELO localhost) ([10.245.246.110]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Aug 2024 01:31:21 -0700 From: Jani Nikula To: Derek Foreman , dri-devel@lists.freedesktop.org Cc: Maxime Ripard , kernel@collabora.com, Helge Deller , linux-fbdev@vger.kernel.org, Derek Foreman Subject: Re: [PATCH v4] drm/connector: hdmi: Fix writing Dynamic Range Mastering infoframes In-Reply-To: <20240827163918.48160-1-derek.foreman@collabora.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20240827163918.48160-1-derek.foreman@collabora.com> Date: Wed, 28 Aug 2024 11:31:15 +0300 Message-ID: <87cyltyros.fsf@intel.com> Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Tue, 27 Aug 2024, Derek Foreman wrote: > The largest infoframe we create is the DRM (Dynamic Range Mastering) > infoframe which is 26 bytes + a 4 byte header, for a total of 30 > bytes. > > With HDMI_MAX_INFOFRAME_SIZE set to 29 bytes, as it is now, we > allocate too little space to pack a DRM infoframe in > write_device_infoframe(), leading to an ENOSPC return from > hdmi_infoframe_pack(), and never calling the connector's > write_infoframe() vfunc. > > Instead of having HDMI_MAX_INFOFRAME_SIZE defined in two places, > replace HDMI_MAX_INFOFRAME_SIZE with HDMI_INFOFRAME_SIZE(MAX) and make > MAX 27 bytes - which is defined by the HDMI specification to be the > largest infoframe payload. > > Fixes: f378b77227bc ("drm/connector: hdmi: Add Infoframes generation") > Fixes: c602e4959a0c ("drm/connector: hdmi: Create Infoframe DebugFS entries") > Superfluous blank line. Can be fixed while applying. Reviewed-by: Jani Nikula > Signed-off-by: Derek Foreman > --- > drivers/gpu/drm/display/drm_hdmi_state_helper.c | 4 +--- > drivers/gpu/drm/drm_debugfs.c | 4 +--- > include/linux/hdmi.h | 9 +++++++++ > 3 files changed, 11 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c > index 7854820089ec..feb7a3a75981 100644 > --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c > +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c > @@ -521,8 +521,6 @@ int drm_atomic_helper_connector_hdmi_check(struct drm_connector *connector, > } > EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_check); > > -#define HDMI_MAX_INFOFRAME_SIZE 29 > - > static int clear_device_infoframe(struct drm_connector *connector, > enum hdmi_infoframe_type type) > { > @@ -563,7 +561,7 @@ static int write_device_infoframe(struct drm_connector *connector, > { > const struct drm_connector_hdmi_funcs *funcs = connector->hdmi.funcs; > struct drm_device *dev = connector->dev; > - u8 buffer[HDMI_MAX_INFOFRAME_SIZE]; > + u8 buffer[HDMI_INFOFRAME_SIZE(MAX)]; > int ret; > int len; > > diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c > index 6b239a24f1df..9d3e6dd68810 100644 > --- a/drivers/gpu/drm/drm_debugfs.c > +++ b/drivers/gpu/drm/drm_debugfs.c > @@ -520,8 +520,6 @@ static const struct file_operations drm_connector_fops = { > .write = connector_write > }; > > -#define HDMI_MAX_INFOFRAME_SIZE 29 > - > static ssize_t > audio_infoframe_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) > { > @@ -579,7 +577,7 @@ static ssize_t _f##_read_infoframe(struct file *filp, \ > struct drm_connector *connector; \ > union hdmi_infoframe *frame; \ > struct drm_device *dev; \ > - u8 buf[HDMI_MAX_INFOFRAME_SIZE]; \ > + u8 buf[HDMI_INFOFRAME_SIZE(MAX)]; \ > ssize_t len = 0; \ > \ > connector = filp->private_data; \ > diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h > index 3bb87bf6bc65..455f855bc084 100644 > --- a/include/linux/hdmi.h > +++ b/include/linux/hdmi.h > @@ -59,6 +59,15 @@ enum hdmi_infoframe_type { > #define HDMI_DRM_INFOFRAME_SIZE 26 > #define HDMI_VENDOR_INFOFRAME_SIZE 4 > > +/* > + * HDMI 1.3a table 5-14 states that the largest InfoFrame_length is 27, > + * not including the packet header or checksum byte. We include the > + * checksum byte in HDMI_INFOFRAME_HEADER_SIZE, so this should allow > + * HDMI_INFOFRAME_SIZE(MAX) to be the largest buffer we could ever need > + * for any HDMI infoframe. > + */ > +#define HDMI_MAX_INFOFRAME_SIZE 27 > + > #define HDMI_INFOFRAME_SIZE(type) \ > (HDMI_INFOFRAME_HEADER_SIZE + HDMI_ ## type ## _INFOFRAME_SIZE) -- Jani Nikula, Intel