v5.19 & v6.0 stable backport request

index 7d6eb9ad7a02..1a30e645c5a7 100644
@@ -135,18 +135,6 @@ static u32 raw_block_offset(const void *bdb, enum bdb_block_id section_id)
 	return block - bdb;
 }
 
-/* size of the block excluding the header */
-static u32 raw_block_size(const void *bdb, enum bdb_block_id section_id)
-{
-	const void *block;
-
-	block = find_raw_section(bdb, section_id);
-	if (!block)
-		return 0;
-
-	return get_blocksize(block);
-}
-
 struct bdb_block_entry {
 	struct list_head node;
 	enum bdb_block_id section_id;

@@ -231,9 +219,14 @@ static bool validate_lfp_data_ptrs(const void *bdb,
 {
 	int fp_timing_size, dvo_timing_size, panel_pnp_id_size, panel_name_size;
 	int data_block_size, lfp_data_size;
+	const void *data_block;
 	int i;
 
-	data_block_size = raw_block_size(bdb, BDB_LVDS_LFP_DATA);
+	data_block = find_raw_section(bdb, BDB_LVDS_LFP_DATA);
+	if (!data_block)
+		return false;
+
+	data_block_size = get_blocksize(data_block);
 	if (data_block_size == 0)
 		return false;
 

@@ -261,21 +254,6 @@ static bool validate_lfp_data_ptrs(const void *bdb,
 	if (16 * lfp_data_size > data_block_size)
 		return false;
 
-	/*
-	 * Except for vlv/chv machines all real VBTs seem to have 6
-	 * unaccounted bytes in the fp_timing table. And it doesn't
-	 * appear to be a really intentional hole as the fp_timing
-	 * 0xffff terminator is always within those 6 missing bytes.
-	 */
-	if (fp_timing_size + dvo_timing_size + panel_pnp_id_size != lfp_data_size &&
-	    fp_timing_size + 6 + dvo_timing_size + panel_pnp_id_size != lfp_data_size)
-		return false;
-
-	if (ptrs->ptr[0].fp_timing.offset + fp_timing_size > ptrs->ptr[0].dvo_timing.offset ||
-	    ptrs->ptr[0].dvo_timing.offset + dvo_timing_size != ptrs->ptr[0].panel_pnp_id.offset ||
-	    ptrs->ptr[0].panel_pnp_id.offset + panel_pnp_id_size != lfp_data_size)
-		return false;
-
 	/* make sure the table entries have uniform size */
 	for (i = 1; i < 16; i++) {
 		if (ptrs->ptr[i].fp_timing.table_size != fp_timing_size ||

@@ -289,6 +267,23 @@ static bool validate_lfp_data_ptrs(const void *bdb,
 			return false;
 	}
 
+	/*
+	 * Except for vlv/chv machines all real VBTs seem to have 6
+	 * unaccounted bytes in the fp_timing table. And it doesn't
+	 * appear to be a really intentional hole as the fp_timing
+	 * 0xffff terminator is always within those 6 missing bytes.
+	 */
+	if (fp_timing_size + 6 + dvo_timing_size + panel_pnp_id_size == lfp_data_size)
+		fp_timing_size += 6;
+
+	if (fp_timing_size + dvo_timing_size + panel_pnp_id_size != lfp_data_size)
+		return false;
+
+	if (ptrs->ptr[0].fp_timing.offset + fp_timing_size != ptrs->ptr[0].dvo_timing.offset ||
+	    ptrs->ptr[0].dvo_timing.offset + dvo_timing_size != ptrs->ptr[0].panel_pnp_id.offset ||
+	    ptrs->ptr[0].panel_pnp_id.offset + panel_pnp_id_size != lfp_data_size)
+		return false;
+
 	/* make sure the tables fit inside the data block */
 	for (i = 0; i < 16; i++) {
 		if (ptrs->ptr[i].fp_timing.offset + fp_timing_size > data_block_size ||

@@ -300,6 +295,15 @@ static bool validate_lfp_data_ptrs(const void *bdb,
 	if (ptrs->panel_name.offset + 16 * panel_name_size > data_block_size)
 		return false;
 
+	/* make sure fp_timing terminators are present at expected locations */
+	for (i = 0; i < 16; i++) {
+		const u16 *t = data_block + ptrs->ptr[i].fp_timing.offset +
+			fp_timing_size - 2;
+
+		if (*t != 0xffff)
+			return false;
+	}
+
 	return true;
 }
 

index 1a30e645c5a7..459571e2cc57 100644
@@ -337,18 +337,6 @@ static bool fixup_lfp_data_ptrs(const void *bdb, void *ptrs_block)
 	return validate_lfp_data_ptrs(bdb, ptrs);
 }
 
-static const void *find_fp_timing_terminator(const u8 *data, int size)
-{
-	int i;
-
-	for (i = 0; i < size - 1; i++) {
-		if (data[i] == 0xff && data[i+1] == 0xff)
-			return &data[i];
-	}
-
-	return NULL;
-}
-
 static int make_lfp_data_ptr(struct lvds_lfp_data_ptr_table *table,
 			     int table_size, int total_size)
 {

@@ -372,11 +360,22 @@ static void next_lfp_data_ptr(struct lvds_lfp_data_ptr_table *next,
 static void *generate_lfp_data_ptrs(struct drm_i915_private *i915,
 				    const void *bdb)
 {
-	int i, size, table_size, block_size, offset;
-	const void *t0, *t1, *block;
+	int i, size, table_size, block_size, offset, fp_timing_size;
 	struct bdb_lvds_lfp_data_ptrs *ptrs;
+	const void *block;
 	void *ptrs_block;
 
+	/*
+	 * The hardcoded fp_timing_size is only valid for
+	 * modernish VBTs. All older VBTs definitely should
+	 * include block 41 and thus we don't need to
+	 * generate one.
+	 */
+	if (i915->vbt.version < 155)
+		return NULL;
+
+	fp_timing_size = 38;
+
 	block = find_raw_section(bdb, BDB_LVDS_LFP_DATA);
 	if (!block)
 		return NULL;

@@ -385,17 +384,8 @@ static void *generate_lfp_data_ptrs(struct drm_i915_private *i915,
 
 	block_size = get_blocksize(block);
 
-	size = block_size;
-	t0 = find_fp_timing_terminator(block, size);
-	if (!t0)
-		return NULL;
-
-	size -= t0 - block - 2;
-	t1 = find_fp_timing_terminator(t0 + 2, size);
-	if (!t1)
-		return NULL;
-
-	size = t1 - t0;
+	size = fp_timing_size + sizeof(struct lvds_dvo_timing) +
+		sizeof(struct lvds_pnp_id);
 	if (size * 16 > block_size)
 		return NULL;
 

@@ -413,7 +403,7 @@ static void *generate_lfp_data_ptrs(struct drm_i915_private *i915,
 	table_size = sizeof(struct lvds_dvo_timing);
 	size = make_lfp_data_ptr(&ptrs->ptr[0].dvo_timing, table_size, size);
 
-	table_size = t0 - block + 2;
+	table_size = fp_timing_size;
 	size = make_lfp_data_ptr(&ptrs->ptr[0].fp_timing, table_size, size);
 
 	if (ptrs->ptr[0].fp_timing.table_size)

@@ -428,14 +418,14 @@ static void *generate_lfp_data_ptrs(struct drm_i915_private *i915,
 		return NULL;
 	}
 
-	size = t1 - t0;
+	size = fp_timing_size + sizeof(struct lvds_dvo_timing) +
+		sizeof(struct lvds_pnp_id);
 	for (i = 1; i < 16; i++) {
 		next_lfp_data_ptr(&ptrs->ptr[i].fp_timing, &ptrs->ptr[i-1].fp_timing, size);
 		next_lfp_data_ptr(&ptrs->ptr[i].dvo_timing, &ptrs->ptr[i-1].dvo_timing, size);
 		next_lfp_data_ptr(&ptrs->ptr[i].panel_pnp_id, &ptrs->ptr[i-1].panel_pnp_id, size);
 	}
 
-	size = t1 - t0;
 	table_size = sizeof(struct lvds_lfp_panel_name);
 
 	if (16 * (size + table_size) <= block_size) {