[Intel-gfx] [PATCH 4/4] drm/i915: fix link rates reported for SKL

[Sivakumar Thulasimani]

From: "Thulasimani,Sivakumar" <sivakumar.thulasimani at intel.com>

This patch fixes the bug that SKL SKUs before B0 might return
HBR2 as supported even though it is not supposed to be enabled
on such platforms.

v2: optimize if else condition (Jani)

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 8bc6361..32bf961 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1224,21 +1224,24 @@ static bool intel_dp_source_supports_hbr2(struct drm_device *dev)
 static int
 intel_dp_source_rates(struct drm_device *dev, const int **source_rates)
 {
+	int size;
+
 	if (IS_BROXTON(dev)) {
 		*source_rates = bxt_rates;
-		return ARRAY_SIZE(bxt_rates);
+		size =  ARRAY_SIZE(bxt_rates);
 	} else if (IS_SKYLAKE(dev)) {
 		*source_rates = skl_rates;
-		return ARRAY_SIZE(skl_rates);
+		size = ARRAY_SIZE(skl_rates);
+	} else {
+		*source_rates = default_rates;
+		size = ARRAY_SIZE(default_rates);
 	}
 
-	*source_rates = default_rates;
-
 	/* This depends on the fact that 5.4 is last value in the array */
-	if (intel_dp_source_supports_hbr2(dev))
-		return (DP_LINK_BW_5_4 >> 3) + 1;
-	else
-		return (DP_LINK_BW_2_7 >> 3) + 1;
+	if (!intel_dp_source_supports_hbr2(dev))
+		size--;
+
+	return size;
 }
 
 static void
-- 
1.7.9.5