[PATCH 05/17] drm/amd/display: Fix Mode Cutoff in DSC Passthrough to DP2.1 Monitor

[Rodrigo Siqueira]

From: Fangzhi Zuo <Jerry.Zuo at amd.com>

Source --> DP2.1 MST hub --> DP1.4/2.1 monitor

When change from DP1.4 to DP2.1 from monitor manual, modes higher than
4k120 are all cutoff by mode validation. Switch back to DP1.4 gets all
the modes up to 4k240 available to be enabled by dsc passthrough.

[why]
Compared to DP1.4 link from hub to monitor, DP2.1 link has larger
full_pbn value that causes overflow in the process of doing conversion
from pbn to kbps.

[how]
Change the data type accordingly to fit into the data limit during
conversion calculation.

Reviewed-by: Wayne Lin <wayne.lin at amd.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo at amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigo.siqueira at amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index 6e4359490613..ca864f71ae66 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -1688,16 +1688,16 @@ int pre_validate_dsc(struct drm_atomic_state *state,
 	return ret;
 }
 
-static unsigned int kbps_from_pbn(unsigned int pbn)
+static uint32_t kbps_from_pbn(unsigned int pbn)
 {
-	unsigned int kbps = pbn;
+	uint64_t kbps = (uint64_t)pbn;
 
 	kbps *= (1000000 / PEAK_FACTOR_X1000);
 	kbps *= 8;
 	kbps *= 54;
 	kbps /= 64;
 
-	return kbps;
+	return (uint32_t)kbps;
 }
 
 static bool is_dsc_common_config_possible(struct dc_stream_state *stream,
-- 
2.45.2