diff --git a/bdk/input/joycon.c b/bdk/input/joycon.c
index 1b971f8..2e95414 100644
--- a/bdk/input/joycon.c
+++ b/bdk/input/joycon.c
@@ -1,7 +1,7 @@
 /*
  * Joy-Con UART driver for Nintendo Switch
  *
- * Copyright (c) 2019 CTCaer
+ * Copyright (c) 2019-2021 CTCaer
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -881,14 +881,14 @@ void jc_init_hw()
 	pinmux_config_uart(UART_C);
 
 	// Ease the stress to APB.
-	bpmp_clk_rate_set(BPMP_CLK_NORMAL);
+	bpmp_freq_t prev_fid = bpmp_clk_rate_set(BPMP_CLK_NORMAL);
 
 	// Enable UART B and C clocks.
 	clock_enable_uart(UART_B);
 	clock_enable_uart(UART_C);
 
 	// Restore OC.
-	bpmp_clk_rate_set(BPMP_CLK_DEFAULT_BOOST);
+	bpmp_clk_rate_set(prev_fid);
 
 	// Turn Joy-Con detect on.
 	gpio_config(GPIO_PORT_G, GPIO_PIN_0, GPIO_MODE_GPIO);
diff --git a/bdk/sec/tsec.c b/bdk/sec/tsec.c
index 124cfa3..216164d 100644
--- a/bdk/sec/tsec.c
+++ b/bdk/sec/tsec.c
@@ -70,7 +70,7 @@ int tsec_query(void *tsec_keys, u8 kb, tsec_ctxt_t *tsec_ctxt)
 	u32 *pkg11_magic_off;
 
 	bpmp_mmu_disable();
-	bpmp_clk_rate_set(BPMP_CLK_NORMAL);
+	bpmp_freq_t prev_fid = bpmp_clk_rate_set(BPMP_CLK_NORMAL);
 
 	// Enable clocks.
 	clock_enable_host1x();
@@ -284,7 +284,7 @@ out:;
 	clock_disable_sor_safe();
 	clock_disable_tsec();
 	bpmp_mmu_enable();
-	bpmp_clk_rate_set(BPMP_CLK_DEFAULT_BOOST);
+	bpmp_clk_rate_set(prev_fid);
 
 	return res;
 }
diff --git a/bdk/soc/bpmp.c b/bdk/soc/bpmp.c
index 2e1819d..fc0e412 100644
--- a/bdk/soc/bpmp.c
+++ b/bdk/soc/bpmp.c
@@ -1,7 +1,7 @@
 /*
  * BPMP-Lite Cache/MMU and Frequency driver for Tegra X1
  *
- * Copyright (c) 2019-2020 CTCaer
+ * Copyright (c) 2019-2021 CTCaer
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -212,43 +212,45 @@ const u8 pll_divn[] = {
 	//95   // BPMP_CLK_DEV_BOOST: 608MHz 49% - 152MHz APB.
 };
 
-bpmp_freq_t bpmp_clock_set = BPMP_CLK_NORMAL;
+bpmp_freq_t bpmp_fid_current = BPMP_CLK_NORMAL;
 
 void bpmp_clk_rate_get()
 {
 	bool clk_src_is_pllp = ((CLOCK(CLK_RST_CONTROLLER_SCLK_BURST_POLICY) >> 4) & 7) == 3;
 
 	if (clk_src_is_pllp)
-		bpmp_clock_set = BPMP_CLK_NORMAL;
+		bpmp_fid_current = BPMP_CLK_NORMAL;
 	else
 	{
-		bpmp_clock_set = BPMP_CLK_HIGH_BOOST;
+		bpmp_fid_current = BPMP_CLK_HIGH_BOOST;
 
 		u8 pll_divn_curr = (CLOCK(CLK_RST_CONTROLLER_PLLC_BASE) >> 10) & 0xFF;
 		for (u32 i = 1; i < sizeof(pll_divn); i++)
 		{
 			if (pll_divn[i] == pll_divn_curr)
 			{
-				bpmp_clock_set = i;
+				bpmp_fid_current = i;
 				break;
 			}
 		}
 	}
 }
 
-void bpmp_clk_rate_set(bpmp_freq_t fid)
+bpmp_freq_t bpmp_clk_rate_set(bpmp_freq_t fid)
 {
+	bpmp_freq_t prev_fid = bpmp_fid_current;
+
 	if (fid > (BPMP_CLK_MAX - 1))
 		fid = BPMP_CLK_MAX - 1;
 
-	if (bpmp_clock_set == fid)
-		return;
+	if (prev_fid == fid)
+		return prev_fid;
 
 	if (fid)
 	{
-		if (bpmp_clock_set)
+		if (prev_fid)
 		{
-			// Restore to PLLP source during PLLC4 configuration.
+			// Restore to PLLP source during PLLC configuration.
 			CLOCK(CLK_RST_CONTROLLER_SCLK_BURST_POLICY) = 0x20003333; // PLLP_OUT.
 			msleep(1); // Wait a bit for clock source change.
 		}
@@ -269,7 +271,10 @@ void bpmp_clk_rate_set(bpmp_freq_t fid)
 		// Disable PLLC to save power.
 		clock_disable_pllc();
 	}
-	bpmp_clock_set = fid;
+	bpmp_fid_current = fid;
+
+	// Return old fid in case of temporary swap.
+	return prev_fid;
 }
 
 // The following functions halt BPMP to reduce power while sleeping.
diff --git a/bdk/soc/bpmp.h b/bdk/soc/bpmp.h
index 81f000b..0f80150 100644
--- a/bdk/soc/bpmp.h
+++ b/bdk/soc/bpmp.h
@@ -1,7 +1,7 @@
 /*
  * BPMP-Lite Cache/MMU and Frequency driver for Tegra X1
  *
- * Copyright (c) 2019-2020 CTCaer
+ * Copyright (c) 2019-2021 CTCaer
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -53,6 +53,7 @@ typedef enum
 	BPMP_CLK_MAX
 } bpmp_freq_t;
 
+#define BPMP_CLK_LOWER_BOOST   BPMP_CLK_SUPER_BOOST
 #define BPMP_CLK_DEFAULT_BOOST BPMP_CLK_HYPER_BOOST
 
 void bpmp_mmu_maintenance(u32 op, bool force);
@@ -60,7 +61,7 @@ void bpmp_mmu_set_entry(int idx, bpmp_mmu_entry_t *entry, bool apply);
 void bpmp_mmu_enable();
 void bpmp_mmu_disable();
 void bpmp_clk_rate_get();
-void bpmp_clk_rate_set(bpmp_freq_t fid);
+bpmp_freq_t bpmp_clk_rate_set(bpmp_freq_t fid);
 void bpmp_usleep(u32 us);
 void bpmp_msleep(u32 ms);
 void bpmp_halt();