From bf1a5fd2eccf20b19941b8461ce9c90899054bd5 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 18 Aug 2015 12:33:36 +0300 Subject: [PATCH] Revert "drm/i915: Allow parsing of variable size child device entries from VBT" MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This reverts commit 047fe6e6db9161e69271f56daaafdaf2add023b1 Author: David Weinehall Date: Tue Aug 4 16:55:52 2015 +0300 drm/i915: Allow parsing of variable size child device entries from VBT That commit is not valid for v4.2, however it will be valid for v4.3. It was simply queued too early. The referenced regressing commit is just fine until the size of struct common_child_dev_config changes, and that won't happen until v4.3. Indeed, the expected size checks here rely on the increased size of the struct, breaking new platforms. Fixes: 047fe6e6db91 ("drm/i915: Allow parsing of variable size child device entries from VBT") Cc: Daniel Vetter Cc: David Weinehall Cc: Ville Syrjälä Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_bios.c | 27 ++++----------------------- 1 file changed, 4 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c index 3dcd59e694db..198fc3c3291b 100644 --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -1075,34 +1075,15 @@ parse_device_mapping(struct drm_i915_private *dev_priv, const union child_device_config *p_child; union child_device_config *child_dev_ptr; int i, child_device_num, count; - u8 expected_size; - u16 block_size; + u16 block_size; p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS); if (!p_defs) { DRM_DEBUG_KMS("No general definition block is found, no devices defined.\n"); return; } - if (bdb->version < 195) { - expected_size = 33; - } else if (bdb->version == 195) { - expected_size = 37; - } else if (bdb->version <= 197) { - expected_size = 38; - } else { - expected_size = 38; - DRM_DEBUG_DRIVER("Expected child_device_config size for BDB version %u not known; assuming %u\n", - expected_size, bdb->version); - } - - if (expected_size > sizeof(*p_child)) { - DRM_ERROR("child_device_config cannot fit in p_child\n"); - return; - } - - if (p_defs->child_dev_size != expected_size) { - DRM_ERROR("Size mismatch; child_device_config size=%u (expected %u); bdb->version: %u\n", - p_defs->child_dev_size, expected_size, bdb->version); + if (p_defs->child_dev_size < sizeof(*p_child)) { + DRM_ERROR("General definiton block child device size is too small.\n"); return; } /* get the block size of general definitions */ @@ -1149,7 +1130,7 @@ parse_device_mapping(struct drm_i915_private *dev_priv, child_dev_ptr = dev_priv->vbt.child_dev + count; count++; - memcpy(child_dev_ptr, p_child, p_defs->child_dev_size); + memcpy(child_dev_ptr, p_child, sizeof(*p_child)); } return; } -- 2.30.2