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 72B31C5321E for ; Mon, 26 Aug 2024 08:48:52 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E482A10E159; Mon, 26 Aug 2024 08:48:51 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="P+ow5oZZ"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8968110E159 for ; Mon, 26 Aug 2024 08:48:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1724662130; x=1756198130; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=ivDrXDjZCvz0itNYQSrMVAf6h59DsHsxfzGPHAE7xRY=; b=P+ow5oZZ68klKh5xL+XuXF8if+pCMoq10lPWllqzpMAiRfIFjDhQg7oA 4T4e1ByRM/pgSL1LlV3pUKV7OnkwiDtkzvSqbyFMJaC13+9Npbuc2TCV7 rR+8eaz5dWt3bOeDXtDXXVTVccyMvIpKhBn8WSaVliK2TrYgmOXQ9WdJE 9QjdTWQkQqInYkuQnJnsMOlnL2MdykBU1RRosfj9/LuXDYRfy9P1diK1H h/c4mVUkUApmrHbXHt5QsyOdiGWSrc0V/j/9inPg38PcQSHm15rJSI24/ XLiX72iPuapbjLBbCLSjv/+mdshGhwW6/1nFFgSPCNr2+WPsPF1MXjDXD Q==; X-CSE-ConnectionGUID: I/fxiJOOSEmufjnybteOwQ== X-CSE-MsgGUID: hqCYA7GzQZSjHqdTHwmG/Q== X-IronPort-AV: E=McAfee;i="6700,10204,11175"; a="33637142" X-IronPort-AV: E=Sophos;i="6.10,177,1719903600"; d="scan'208";a="33637142" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2024 01:48:50 -0700 X-CSE-ConnectionGUID: 0vx/ju4ORuSGax8Dbe0qCg== X-CSE-MsgGUID: 50Dv08qmT8OMDmfHS1js4Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,177,1719903600"; d="scan'208";a="62139246" Received: from sschumil-mobl2.ger.corp.intel.com (HELO localhost) ([10.245.246.113]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2024 01:48:47 -0700 From: Jani Nikula To: Derek Foreman , dri-devel@lists.freedesktop.org Cc: Maxime Ripard , kernel@collabora.com, Derek Foreman Subject: Re: [PATCH v2] drm/connector: hdmi: Increase HDMI_MAX_INFOFRAME_SIZE to 30 In-Reply-To: <20240823164621.385651-1-derek.foreman@collabora.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20240823164621.385651-1-derek.foreman@collabora.com> Date: Mon, 26 Aug 2024 11:48:34 +0300 Message-ID: <87bk1f3c0t.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, 23 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. > > Increase HDMI_MAX_INFOFRAME_SIZE to 30 so we can successfully > write DRM infoframes. > > The drm_debugfs code is similarly updated. > > Signed-off-by: Derek Foreman Okay, thanks for the info. Looking into it, I think keeping this in two places and disconnected from the actual infoframe size definitions is hard to maintain. Maybe something like this: 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..3a442a59919e 100644 --- a/include/linux/hdmi.h +++ b/include/linux/hdmi.h @@ -59,6 +59,9 @@ enum hdmi_infoframe_type { #define HDMI_DRM_INFOFRAME_SIZE 26 #define HDMI_VENDOR_INFOFRAME_SIZE 4 +/* The biggest infoframe size */ +#define HDMI_MAX_INFOFRAME_SIZE HDMI_DRM_INFOFRAME_SIZE + #define HDMI_INFOFRAME_SIZE(type) \ (HDMI_INFOFRAME_HEADER_SIZE + HDMI_ ## type ## _INFOFRAME_SIZE) > --- > drivers/gpu/drm/display/drm_hdmi_state_helper.c | 2 +- > drivers/gpu/drm/drm_debugfs.c | 2 +- > 2 files changed, 2 insertions(+), 2 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..cc7747d33fdf 100644 > --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c > +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c > @@ -521,7 +521,7 @@ 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 > +#define HDMI_MAX_INFOFRAME_SIZE 30 > > static int clear_device_infoframe(struct drm_connector *connector, > enum hdmi_infoframe_type type) > diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c > index 6b239a24f1df..3439fd65275a 100644 > --- a/drivers/gpu/drm/drm_debugfs.c > +++ b/drivers/gpu/drm/drm_debugfs.c > @@ -520,7 +520,7 @@ static const struct file_operations drm_connector_fops = { > .write = connector_write > }; > > -#define HDMI_MAX_INFOFRAME_SIZE 29 > +#define HDMI_MAX_INFOFRAME_SIZE 30 > > static ssize_t > audio_infoframe_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) -- Jani Nikula, Intel