1 files changed, 83 insertions, 59 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 927442a11925..61abef8a8119 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -74,7 +74,7 @@ get_blocksize(void *p)
 
 static void
 fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
-			struct lvds_dvo_timing *dvo_timing)
+			const struct lvds_dvo_timing *dvo_timing)
 {
 	panel_fixed_mode->hdisplay = (dvo_timing->hactive_hi << 8) |
 		dvo_timing->hactive_lo;
@@ -115,20 +115,75 @@ fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
 	drm_mode_set_name(panel_fixed_mode);
 }
 
+static bool
+lvds_dvo_timing_equal_size(const struct lvds_dvo_timing *a,
+			   const struct lvds_dvo_timing *b)
+{
+	if (a->hactive_hi != b->hactive_hi ||
+	    a->hactive_lo != b->hactive_lo)
+		return false;
+
+	if (a->hsync_off_hi != b->hsync_off_hi ||
+	    a->hsync_off_lo != b->hsync_off_lo)
+		return false;
+
+	if (a->hsync_pulse_width != b->hsync_pulse_width)
+		return false;
+
+	if (a->hblank_hi != b->hblank_hi ||
+	    a->hblank_lo != b->hblank_lo)
+		return false;
+
+	if (a->vactive_hi != b->vactive_hi ||
+	    a->vactive_lo != b->vactive_lo)
+		return false;
+
+	if (a->vsync_off != b->vsync_off)
+		return false;
+
+	if (a->vsync_pulse_width != b->vsync_pulse_width)
+		return false;
+
+	if (a->vblank_hi != b->vblank_hi ||
+	    a->vblank_lo != b->vblank_lo)
+		return false;
+
+	return true;
+}
+
+static const struct lvds_dvo_timing *
+get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
+		    const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
+		    int index)
+{
+	/*
+	 * the size of fp_timing varies on the different platform.
+	 * So calculate the DVO timing relative offset in LVDS data
+	 * entry to get the DVO timing entry
+	 */
+
+	int lfp_data_size =
+		lvds_lfp_data_ptrs->ptr[1].dvo_timing_offset -
+		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset;
+	int dvo_timing_offset =
+		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset -
+		lvds_lfp_data_ptrs->ptr[0].fp_timing_offset;
+	char *entry = (char *)lvds_lfp_data->data + lfp_data_size * index;
+
+	return (struct lvds_dvo_timing *)(entry + dvo_timing_offset);
+}
+
 /* Try to find integrated panel data */
 static void
 parse_lfp_panel_data(struct drm_i915_private *dev_priv,
 			    struct bdb_header *bdb)
 {
-	struct bdb_lvds_options *lvds_options;
-	struct bdb_lvds_lfp_data *lvds_lfp_data;
-	struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
-	struct bdb_lvds_lfp_data_entry *entry;
-	struct lvds_dvo_timing *dvo_timing;
+	const struct bdb_lvds_options *lvds_options;
+	const struct bdb_lvds_lfp_data *lvds_lfp_data;
+	const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
+	const struct lvds_dvo_timing *panel_dvo_timing;
 	struct drm_display_mode *panel_fixed_mode;
-	int lfp_data_size, dvo_timing_offset;
-	int i, temp_downclock;
-	struct drm_display_mode *temp_mode;
+	int i, downclock;
 
 	lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
 	if (!lvds_options)
@@ -150,75 +205,44 @@ parse_lfp_panel_data(struct drm_i915_private *dev_priv,
 
 	dev_priv->lvds_vbt = 1;
 
-	lfp_data_size = lvds_lfp_data_ptrs->ptr[1].dvo_timing_offset -
-		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset;
-	entry = (struct bdb_lvds_lfp_data_entry *)
-		((uint8_t *)lvds_lfp_data->data + (lfp_data_size *
-						   lvds_options->panel_type));
-	dvo_timing_offset = lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset -
-		lvds_lfp_data_ptrs->ptr[0].fp_timing_offset;
-
-	/*
-	 * the size of fp_timing varies on the different platform.
-	 * So calculate the DVO timing relative offset in LVDS data
-	 * entry to get the DVO timing entry
-	 */
-	dvo_timing = (struct lvds_dvo_timing *)
-			((unsigned char *)entry + dvo_timing_offset);
+	panel_dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
+					       lvds_lfp_data_ptrs,
+					       lvds_options->panel_type);
 
 	panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
 	if (!panel_fixed_mode)
 		return;
 
-	fill_detail_timing_data(panel_fixed_mode, dvo_timing);
+	fill_detail_timing_data(panel_fixed_mode, panel_dvo_timing);
 
 	dev_priv->lfp_lvds_vbt_mode = panel_fixed_mode;
 
 	DRM_DEBUG_KMS("Found panel mode in BIOS VBT tables:\n");
 	drm_mode_debug_printmodeline(panel_fixed_mode);
 
-	temp_mode = kzalloc(sizeof(*temp_mode), GFP_KERNEL);
-	temp_downclock = panel_fixed_mode->clock;
 	/*
-	 * enumerate the LVDS panel timing info entry in VBT to check whether
-	 * the LVDS downclock is found.
+	 * Iterate over the LVDS panel timing info to find the lowest clock
+	 * for the native resolution.
 	 */
+	downclock = panel_dvo_timing->clock;
 	for (i = 0; i < 16; i++) {
-		entry = (struct bdb_lvds_lfp_data_entry *)
-			((uint8_t *)lvds_lfp_data->data + (lfp_data_size * i));
-		dvo_timing = (struct lvds_dvo_timing *)
-			((unsigned char *)entry + dvo_timing_offset);
-
-		fill_detail_timing_data(temp_mode, dvo_timing);
-
-		if (temp_mode->hdisplay == panel_fixed_mode->hdisplay &&
-		temp_mode->hsync_start == panel_fixed_mode->hsync_start &&
-		temp_mode->hsync_end == panel_fixed_mode->hsync_end &&
-		temp_mode->htotal == panel_fixed_mode->htotal &&
-		temp_mode->vdisplay == panel_fixed_mode->vdisplay &&
-		temp_mode->vsync_start == panel_fixed_mode->vsync_start &&
-		temp_mode->vsync_end == panel_fixed_mode->vsync_end &&
-		temp_mode->vtotal == panel_fixed_mode->vtotal &&
-		temp_mode->clock < temp_downclock) {
-			/*
-			 * downclock is already found. But we expect
-			 * to find the lower downclock.
-			 */
-			temp_downclock = temp_mode->clock;
-		}
-		/* clear it to zero */
-		memset(temp_mode, 0, sizeof(*temp_mode));
+		const struct lvds_dvo_timing *dvo_timing;
+
+		dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
+						 lvds_lfp_data_ptrs,
+						 i);
+		if (lvds_dvo_timing_equal_size(dvo_timing, panel_dvo_timing) &&
+		    dvo_timing->clock < downclock)
+			downclock = dvo_timing->clock;
 	}
-	kfree(temp_mode);
-	if (temp_downclock < panel_fixed_mode->clock &&
-	    i915_lvds_downclock) {
+
+	if (downclock < panel_dvo_timing->clock && i915_lvds_downclock) {
 		dev_priv->lvds_downclock_avail = 1;
-		dev_priv->lvds_downclock = temp_downclock;
+		dev_priv->lvds_downclock = downclock * 10;
 		DRM_DEBUG_KMS("LVDS downclock is found in VBT. "
 			      "Normal Clock %dKHz, downclock %dKHz\n",
-			      temp_downclock, panel_fixed_mode->clock);
+			      panel_fixed_mode->clock, 10*downclock);
 	}
-	return;
 }
 
 /* Try to find sdvo panel data */