From 52b69c849ab4a343e696a0e45d557550f15450a6 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Mon, 14 Dec 2015 18:23:46 +0200 Subject: [PATCH] drm/i915: Allow 27 bytes child_dev for VBT <109 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit My 85x has VBT version 108 which has a child dev size of 27 bytes. Let's allow that without printing an error. We still want to reject the actual parsin since for that we need the child device size to be at least 33 bytes. So we should still check for that, but let's make it print a debug message only instead of an error. While at it, toss in a BUILD_BUG_ON() to verify our struct old_child_dev_config is in fact 33 bytes. Signed-off-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/1450110229-30450-8-git-send-email-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula --- drivers/gpu/drm/i915/intel_bios.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c index 15ba52bd2538..1de16f21121a 100644 --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -1157,7 +1157,10 @@ parse_device_mapping(struct drm_i915_private *dev_priv, DRM_DEBUG_KMS("No general definition block is found, no devices defined.\n"); return; } - if (bdb->version < 195) { + if (bdb->version < 109) { + expected_size = 27; + } else if (bdb->version < 195) { + BUILD_BUG_ON(sizeof(struct old_child_dev_config) != 33); expected_size = sizeof(struct old_child_dev_config); } else if (bdb->version == 195) { expected_size = 37; @@ -1170,18 +1173,18 @@ parse_device_mapping(struct drm_i915_private *dev_priv, bdb->version, expected_size); } - /* The legacy sized child device config is the minimum we need. */ - if (p_defs->child_dev_size < sizeof(struct old_child_dev_config)) { - DRM_ERROR("Child device config size %u is too small.\n", - p_defs->child_dev_size); - return; - } - /* Flag an error for unexpected size, but continue anyway. */ if (p_defs->child_dev_size != expected_size) DRM_ERROR("Unexpected child device config size %u (expected %u for VBT version %u)\n", p_defs->child_dev_size, expected_size, bdb->version); + /* The legacy sized child device config is the minimum we need. */ + if (p_defs->child_dev_size < sizeof(struct old_child_dev_config)) { + DRM_DEBUG_KMS("Child device config size %u is too small.\n", + p_defs->child_dev_size); + return; + } + /* get the block size of general definitions */ block_size = get_blocksize(p_defs); /* get the number of child device */ -- 2.30.2