From patchwork Wed Jun 8 07:50:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jani Nikula X-Patchwork-Id: 12872992 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 D0B85C43334 for ; Wed, 8 Jun 2022 07:51:04 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 94BD910EE77; Wed, 8 Jun 2022 07:51:01 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8F8CE10EE71; Wed, 8 Jun 2022 07:51:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1654674660; x=1686210660; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=qXo3+dxVUh1IV0UkSBtqOI/XGvWDIINbClNWbxvPFmU=; b=AbR3jwm0hNtGpghmwh0k3E9IA573sIwpEz6+FZDgxlkAeuiNR15otuuB Vi+hIpQ7HbPPqTBD4/5bXypYMyIkHAV4ZqD0xA3MayGgzRdW1GC4BlxFJ PNHeNUiRxTTDZTX8v9U4LT8Yi5C6MsXFTsLIcHxQMMLNJou4SAsSVoQzZ HpAe1BOE8uakLKBYN3Ry0PPG2VKMjoHk6Ed1oFldHzMJCuYeYF9N+rELB aNZTSCHi+lEEGNZenMJejlc1nHoNxm7f/HtRHcOeU/UPwYIfsggCCqk+t IHAYpEEyymmpA8+su2h0N4Esza4EiW5bF5rA5Ho5DR7k8Zg/3YCXU1Z7A A==; X-IronPort-AV: E=McAfee;i="6400,9594,10371"; a="277645926" X-IronPort-AV: E=Sophos;i="5.91,285,1647327600"; d="scan'208";a="277645926" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2022 00:51:00 -0700 X-IronPort-AV: E=Sophos;i="5.91,285,1647327600"; d="scan'208";a="826808009" Received: from jkosticx-mobl.amr.corp.intel.com (HELO localhost) ([10.252.58.130]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2022 00:50:57 -0700 From: Jani Nikula To: dri-devel@lists.freedesktop.org Subject: [PATCH v2 02/15] drm/edid: abstract cea data block collection size Date: Wed, 8 Jun 2022 10:50:32 +0300 Message-Id: <5339ab3249400a3c41001967e7ff2611b58e0425.1654674560.git.jani.nikula@intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo 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: , Cc: jani.nikula@intel.com, intel-gfx@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Add a function to get the cea data block collection size. Cc: Ville Syrjälä Signed-off-by: Jani Nikula Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/drm_edid.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index c57f6333ea7d..002816509fc8 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4482,6 +4482,20 @@ __cea_db_iter_current_block(const struct cea_db_iter *iter) return NULL; } +/* + * References: + * - CTA-861-H section 7.3.3 CTA Extension Version 3 + */ +static int cea_db_collection_size(const u8 *cta) +{ + u8 d = cta[2]; + + if (d < 4 || d > 127) + return 0; + + return d - 4; +} + /* * References: * - VESA E-EDID v1.4 @@ -4492,15 +4506,19 @@ static const void *__cea_db_iter_edid_next(struct cea_db_iter *iter) const u8 *ext; drm_edid_iter_for_each(ext, &iter->edid_iter) { + int size; + /* Only support CTA Extension revision 3+ */ if (ext[0] != CEA_EXT || cea_revision(ext) < 3) continue; - iter->index = 4; - iter->end = ext[2]; - if (iter->end < 4 || iter->end > 127) + size = cea_db_collection_size(ext); + if (!size) continue; + iter->index = 4; + iter->end = iter->index + size; + return ext; }