[PATCH 10/20] drm/i915/dp: Add functions to get min/max src input bpc with DSC

[Ankit Nautiyal]

Separate out functions for getting maximum and minimum input BPC based
on platforms, when DSC is used.

v2: Use HAS_DSC macro instead of platform check while getting min input
bpc. (Stan)

Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 35 +++++++++++++++++++------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c 
b/drivers/gpu/drm/i915/display/intel_dp.c
index c13efd0b7c98..b414d09b5e80 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1535,6 +1535,18 @@ intel_dp_compute_link_config_wide(struct intel_dp 
*intel_dp,
        return -EINVAL;
 }
 
+static
+u8 intel_dp_dsc_max_src_input_bpc(struct drm_i915_private *i915)
+{
+       /* Max DSC Input BPC for ICL is 10 and for TGL+ is 12 */
+       if (DISPLAY_VER(i915) >= 12)
+               return 12;
+       if (DISPLAY_VER(i915) == 11)
+               return 10;
+
+       return 0;
+}
+
 int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 max_req_bpc)
 {
        struct drm_i915_private *i915 = dp_to_i915(intel_dp);
@@ -1542,11 +1554,12 @@ int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, 
u8 max_req_bpc)
        u8 dsc_bpc[3] = {0};
        u8 dsc_max_bpc;
 
-       /* Max DSC Input BPC for ICL is 10 and for TGL+ is 12 */
-       if (DISPLAY_VER(i915) >= 12)
-               dsc_max_bpc = min_t(u8, 12, max_req_bpc);
-       else
-               dsc_max_bpc = min_t(u8, 10, max_req_bpc);
+       dsc_max_bpc = intel_dp_dsc_max_src_input_bpc(i915);
+
+       if (!dsc_max_bpc)
+               return dsc_max_bpc;
+
+       dsc_max_bpc = min_t(u8, dsc_max_bpc, max_req_bpc);
 
        num_bpc = drm_dp_dsc_sink_supported_input_bpcs(intel_dp->dsc_dpcd,
                                                       dsc_bpc);
@@ -1674,6 +1687,13 @@ static bool intel_dp_dsc_supports_format(struct intel_dp 
*intel_dp,
        return drm_dp_dsc_sink_supports_format(intel_dp->dsc_dpcd, 
sink_dsc_format);
 }
 
+static
+u8 intel_dp_dsc_min_src_input_bpc(struct drm_i915_private *i915)
+{
+       /* Min DSC Input BPC for ICL+ is 8 */
+       return HAS_DSC(i915) ? 8 : 0;
+}
+
 int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
                                struct intel_crtc_state *pipe_config,
                                struct drm_connector_state *conn_state,
@@ -1707,10 +1727,9 @@ int intel_dp_dsc_compute_config(struct intel_dp 
*intel_dp,
                pipe_bpp = pipe_config->pipe_bpp;
        }
 
-       /* Min Input BPC for ICL+ is 8 */
-       if (pipe_bpp < 8 * 3) {
+       if (pipe_bpp < intel_dp_dsc_min_src_input_bpc(dev_priv) * 3) {
                drm_dbg_kms(&dev_priv->drm,
-                           "No DSC support for less than 8bpc\n");
+                           "Computed BPC less than min supported by source for 
DSC\n");
                return -EINVAL;
        }
 
-- 
2.40.1