From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753890Ab1HNQGm (ORCPT ); Sun, 14 Aug 2011 12:06:42 -0400 Received: from cantor2.suse.de ([195.135.220.15]:36377 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753838Ab1HNQGk (ORCPT ); Sun, 14 Aug 2011 12:06:40 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Aug 12 14:05:53 2011 Message-Id: <20110812210553.765965532@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Fri, 12 Aug 2011 14:04:04 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Thomas Reim , Stephen Michaels , Dave Airlie Subject: [19/90] drm: Separate EDID Header Check from EDID Block Check In-Reply-To: <20110812210626.GA4725@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let us know. ------------------ From: Thomas Reim commit 051963d4832ed61e5ae74f5330b0a94489e101b9 upstream. Provides function drm_edid_header_is_valid() for EDID header check and replaces EDID header check part of function drm_edid_block_valid() by a call of drm_edid_header_is_valid(). This is a prerequisite to extend DDC probing, e. g. in function radeon_ddc_probe() for Radeon devices, by a central EDID header check. Tested for kernel 2.6.35, 2.6.38 and 3.0 Signed-off-by: Thomas Reim Reviewed-by: Alex Deucher Acked-by: Stephen Michaels Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_edid.c | 24 ++++++++++++++++++------ include/drm/drm_crtc.h | 1 + 2 files changed, 19 insertions(+), 6 deletions(-) --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -127,6 +127,23 @@ static const u8 edid_header[] = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 }; + /* + * Sanity check the header of the base EDID block. Return 8 if the header + * is perfect, down to 0 if it's totally wrong. + */ +int drm_edid_header_is_valid(const u8 *raw_edid) +{ + int i, score = 0; + + for (i = 0; i < sizeof(edid_header); i++) + if (raw_edid[i] == edid_header[i]) + score++; + + return score; +} +EXPORT_SYMBOL(drm_edid_header_is_valid); + + /* * Sanity check the EDID block (base or extension). Return 0 if the block * doesn't check out, or 1 if it's valid. @@ -139,12 +156,7 @@ drm_edid_block_valid(u8 *raw_edid) struct edid *edid = (struct edid *)raw_edid; if (raw_edid[0] == 0x00) { - int score = 0; - - for (i = 0; i < sizeof(edid_header); i++) - if (raw_edid[i] == edid_header[i]) - score++; - + int score = drm_edid_header_is_valid(raw_edid); if (score == 8) ; else if (score >= 6) { DRM_DEBUG("Fixing EDID header, your hardware may be failing\n"); --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -802,6 +802,7 @@ extern struct drm_display_mode *drm_gtf_ extern int drm_add_modes_noedid(struct drm_connector *connector, int hdisplay, int vdisplay); +extern int drm_edid_header_is_valid(const u8 *raw_edid); extern bool drm_edid_is_valid(struct edid *edid); struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev, int hsize, int vsize, int fresh);