diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 9a712791f309f..ada3773869ff0 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -6918,7 +6918,7 @@ static int dm_encoder_helper_atomic_check(struct drm_encoder *encoder,
 								    max_bpc);
 		bpp = convert_dc_color_depth_into_bpc(color_depth) * 3;
 		clock = adjusted_mode->clock;
-		dm_new_connector_state->pbn = drm_dp_calc_pbn_mode(clock, bpp, false);
+		dm_new_connector_state->pbn = drm_dp_calc_pbn_mode(clock, bpp << 4);
 	}
 
 	dm_new_connector_state->vcpi_slots =
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 d3b13d362edac..9a58e1a4c5f49 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
@@ -1642,7 +1642,7 @@ enum dc_status dm_dp_mst_is_port_support_mode(
 	} else {
 		/* check if mode could be supported within full_pbn */
 		bpp = convert_dc_color_depth_into_bpc(stream->timing.display_color_depth) * 3;
-		pbn = drm_dp_calc_pbn_mode(stream->timing.pix_clk_100hz / 10, bpp, false);
+		pbn = drm_dp_calc_pbn_mode(stream->timing.pix_clk_100hz / 10, bpp << 4);
 
 		if (pbn > aconnector->mst_output_port->full_pbn)
 			return DC_FAIL_BANDWIDTH_VALIDATE;
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 0e0d0e76de065..772b00ebd57bd 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -4718,13 +4718,12 @@ EXPORT_SYMBOL(drm_dp_check_act_status);
 
 /**
  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
- * @clock: dot clock for the mode
- * @bpp: bpp for the mode.
- * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
+ * @clock: dot clock
+ * @bpp: bpp as .4 binary fixed point
  *
  * This uses the formula in the spec to calculate the PBN value for a mode.
  */
-int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
+int drm_dp_calc_pbn_mode(int clock, int bpp)
 {
 	/*
 	 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
@@ -4735,18 +4734,9 @@ int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
 	 * peak_kbps *= (1006/1000)
 	 * peak_kbps *= (64/54)
 	 * peak_kbps *= 8    convert to bytes
-	 *
-	 * If the bpp is in units of 1/16, further divide by 16. Put this
-	 * factor in the numerator rather than the denominator to avoid
-	 * integer overflow
 	 */
-
-	if (dsc)
-		return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
-					8 * 54 * 1000 * 1000);
-
-	return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
-				8 * 54 * 1000 * 1000);
+	return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006 >> 4),
+				1000 * 8 * 54 * 1000);
 }
 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 851b312bd8449..5bf45a2a85b0e 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -106,8 +106,7 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder,
 			continue;
 
 		crtc_state->pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock,
-						       dsc ? bpp << 4 : bpp,
-						       dsc);
+						       bpp << 4);
 
 		slots = drm_dp_atomic_find_time_slots(state, &intel_dp->mst_mgr,
 						      connector->port,
@@ -975,7 +974,7 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
 		return ret;
 
 	if (mode_rate > max_rate || mode->clock > max_dotclk ||
-	    drm_dp_calc_pbn_mode(mode->clock, min_bpp, false) > port->full_pbn) {
+	    drm_dp_calc_pbn_mode(mode->clock, min_bpp << 4) > port->full_pbn) {
 		*status = MODE_CLOCK_HIGH;
 		return 0;
 	}
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index d2be40337b92e..153717e1df1a2 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -982,8 +982,7 @@ nv50_msto_atomic_check(struct drm_encoder *encoder,
 		const int clock = crtc_state->adjusted_mode.clock;
 
 		asyh->or.bpc = connector->display_info.bpc;
-		asyh->dp.pbn = drm_dp_calc_pbn_mode(clock, asyh->or.bpc * 3,
-						    false);
+		asyh->dp.pbn = drm_dp_calc_pbn_mode(clock, asyh->or.bpc * 3 << 4);
 	}
 
 	mst_state = drm_atomic_get_mst_topology_state(state, &mstm->mgr);
diff --git a/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c b/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
index 545beea33e8c7..e3c818dfc0e6d 100644
--- a/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
@@ -42,13 +42,13 @@ static const struct drm_dp_mst_calc_pbn_mode_test drm_dp_mst_calc_pbn_mode_cases
 		.clock = 332880,
 		.bpp = 24,
 		.dsc = true,
-		.expected = 50
+		.expected = 1191
 	},
 	{
 		.clock = 324540,
 		.bpp = 24,
 		.dsc = true,
-		.expected = 49
+		.expected = 1161
 	},
 };
 
@@ -56,7 +56,7 @@ static void drm_test_dp_mst_calc_pbn_mode(struct kunit *test)
 {
 	const struct drm_dp_mst_calc_pbn_mode_test *params = test->param_value;
 
-	KUNIT_EXPECT_EQ(test, drm_dp_calc_pbn_mode(params->clock, params->bpp, params->dsc),
+	KUNIT_EXPECT_EQ(test, drm_dp_calc_pbn_mode(params->clock, params->bpp << 4),
 			params->expected);
 }
 
diff --git a/include/drm/display/drm_dp_mst_helper.h b/include/drm/display/drm_dp_mst_helper.h
index 4429d3b1745b6..655862b3d2a49 100644
--- a/include/drm/display/drm_dp_mst_helper.h
+++ b/include/drm/display/drm_dp_mst_helper.h
@@ -842,7 +842,7 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector,
 int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
 			     int link_rate, int link_lane_count);
 
-int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc);
+int drm_dp_calc_pbn_mode(int clock, int bpp);
 
 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap);
 
