diff --git a/PKGBUILD b/PKGBUILD
index 5c8d2cf..440f1a9 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -5,7 +5,7 @@ pkgbase=linux               # Build stock -ARCH kernel
 #pkgbase=linux-custom       # Build kernel with a different name
 _srcname=linux-4.15
 pkgver=4.15.1
-pkgrel=3
+pkgrel=4
 arch=('x86_64')
 url="https://www.kernel.org/"
 license=('GPL2')
@@ -29,7 +29,7 @@ sha256sums=('5a26478906d5005f4f809402e981518d2b8844949199f60c4b6e1f986ca2a769'
             'SKIP'
             '202a0a34f221ae335de096c292927d7a7d4bcdbc2dd46d43b8a5f6420f95a0cf'
             'SKIP'
-            '76a984ab37d6f2f58f9404ac082fa8819c60e2d26e33a69446e97c4b7258beda'
+            '57400ed3b21281ad84d72756ce98815c8f6073b8c53b3bc6d73120c47902a263'
             'ae2e95db94ef7176207c690224169594d49445e04249d2499e9d2fbc117a0b21'
             '75f99f5239e03238f88d1a834c50043ec32b1dc568f2cc291b07d04718483919'
             'ad6344badc91ad0630caacde83f7f9b97276f80d26a20619a87952be65492c65'
diff --git a/config b/config
index 1bafe6f..98443fc 100644
--- a/config
+++ b/config
@@ -1,6 +1,6 @@
 #
 # Automatically generated file; DO NOT EDIT.
-# Linux/x86 4.15.1-3 Kernel Configuration
+# Linux/x86 4.15.1-4 Kernel Configuration
 #
 CONFIG_64BIT=y
 CONFIG_X86_64=y
@@ -136,11 +136,11 @@ CONFIG_CPU_ISOLATION=y
 #
 # RCU Subsystem
 #
-CONFIG_TREE_RCU=y
+CONFIG_PREEMPT_RCU=y
 CONFIG_RCU_EXPERT=y
 CONFIG_SRCU=y
 CONFIG_TREE_SRCU=y
-# CONFIG_TASKS_RCU is not set
+CONFIG_TASKS_RCU=y
 CONFIG_RCU_STALL_COMMON=y
 CONFIG_RCU_NEED_SEGCBLIST=y
 CONFIG_CONTEXT_TRACKING=y
@@ -148,6 +148,8 @@ CONFIG_CONTEXT_TRACKING=y
 CONFIG_RCU_FANOUT=32
 CONFIG_RCU_FANOUT_LEAF=16
 CONFIG_RCU_FAST_NO_HZ=y
+CONFIG_RCU_BOOST=y
+CONFIG_RCU_BOOST_DELAY=500
 CONFIG_RCU_NOCB_CPU=y
 CONFIG_BUILD_BIN2C=y
 CONFIG_IKCONFIG=y
@@ -222,7 +224,7 @@ CONFIG_PRINTK=y
 CONFIG_PRINTK_NMI=y
 CONFIG_BUG=y
 CONFIG_ELF_CORE=y
-# CONFIG_PCSPKR_PLATFORM is not set
+CONFIG_PCSPKR_PLATFORM=y
 CONFIG_BASE_FULL=y
 CONFIG_FUTEX=y
 CONFIG_FUTEX_PI=y
@@ -261,14 +263,14 @@ CONFIG_SLUB=y
 CONFIG_SLAB_MERGE_DEFAULT=y
 CONFIG_SLAB_FREELIST_RANDOM=y
 CONFIG_SLAB_FREELIST_HARDENED=y
-CONFIG_SLUB_CPU_PARTIAL=y
+# CONFIG_SLUB_CPU_PARTIAL is not set
 CONFIG_SYSTEM_DATA_VERIFICATION=y
 CONFIG_PROFILING=y
 CONFIG_TRACEPOINTS=y
 CONFIG_CRASH_CORE=y
 CONFIG_KEXEC_CORE=y
 CONFIG_OPROFILE=m
-CONFIG_OPROFILE_EVENT_MULTIPLEX=y
+# CONFIG_OPROFILE_EVENT_MULTIPLEX is not set
 CONFIG_HAVE_OPROFILE=y
 CONFIG_OPROFILE_NMI_TIMER=y
 CONFIG_KPROBES=y
@@ -439,11 +441,7 @@ CONFIG_BFQ_GROUP_IOSCHED=y
 CONFIG_PREEMPT_NOTIFIERS=y
 CONFIG_PADATA=y
 CONFIG_ASN1=y
-CONFIG_INLINE_SPIN_UNLOCK_IRQ=y
-CONFIG_INLINE_READ_UNLOCK=y
-CONFIG_INLINE_READ_UNLOCK_IRQ=y
-CONFIG_INLINE_WRITE_UNLOCK=y
-CONFIG_INLINE_WRITE_UNLOCK_IRQ=y
+CONFIG_UNINLINE_SPIN_UNLOCK=y
 CONFIG_ARCH_SUPPORTS_ATOMIC_RMW=y
 CONFIG_MUTEX_SPIN_ON_OWNER=y
 CONFIG_RWSEM_SPIN_ON_OWNER=y
@@ -523,8 +521,9 @@ CONFIG_SCHED_SMT=y
 CONFIG_SCHED_MC=y
 CONFIG_SCHED_MC_PRIO=y
 # CONFIG_PREEMPT_NONE is not set
-CONFIG_PREEMPT_VOLUNTARY=y
-# CONFIG_PREEMPT is not set
+# CONFIG_PREEMPT_VOLUNTARY is not set
+CONFIG_PREEMPT=y
+CONFIG_PREEMPT_COUNT=y
 CONFIG_X86_LOCAL_APIC=y
 CONFIG_X86_IO_APIC=y
 CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS=y
@@ -3760,6 +3759,7 @@ CONFIG_INPUT_ARIZONA_HAPTICS=m
 CONFIG_INPUT_ATMEL_CAPTOUCH=m
 CONFIG_INPUT_BMA150=m
 CONFIG_INPUT_E3X0_BUTTON=m
+CONFIG_INPUT_PCSPKR=m
 CONFIG_INPUT_MAX77693_HAPTIC=m
 CONFIG_INPUT_MAX8925_ONKEY=m
 CONFIG_INPUT_MAX8997_HAPTIC=m
@@ -4989,6 +4989,7 @@ CONFIG_REGULATOR_WM8400=m
 CONFIG_REGULATOR_WM8994=m
 CONFIG_CEC_CORE=m
 CONFIG_CEC_NOTIFIER=y
+CONFIG_CEC_PIN=y
 CONFIG_RC_CORE=m
 CONFIG_RC_MAP=m
 CONFIG_RC_DECODERS=y
@@ -5340,6 +5341,7 @@ CONFIG_VIDEO_VIVID_MAX_DEVS=64
 CONFIG_VIDEO_VIM2M=m
 CONFIG_DVB_PLATFORM_DRIVERS=y
 CONFIG_CEC_PLATFORM_DRIVERS=y
+CONFIG_CEC_GPIO=m
 CONFIG_SDR_PLATFORM_DRIVERS=y
 
 #
@@ -6047,6 +6049,7 @@ CONFIG_SND_OPL3_LIB_SEQ=m
 CONFIG_SND_VX_LIB=m
 CONFIG_SND_AC97_CODEC=m
 CONFIG_SND_DRIVERS=y
+# CONFIG_SND_PCSP is not set
 CONFIG_SND_DUMMY=m
 CONFIG_SND_ALOOP=m
 CONFIG_SND_VIRMIDI=m
@@ -7679,41 +7682,7 @@ CONFIG_CRYPTO_SKEIN=m
 CONFIG_UNISYSSPAR=y
 # CONFIG_UNISYS_VISORBUS is not set
 CONFIG_COMMON_CLK_XLNX_CLKWZRD=m
-CONFIG_FB_TFT=m
-# CONFIG_FB_TFT_AGM1264K_FL is not set
-# CONFIG_FB_TFT_BD663474 is not set
-# CONFIG_FB_TFT_HX8340BN is not set
-# CONFIG_FB_TFT_HX8347D is not set
-# CONFIG_FB_TFT_HX8353D is not set
-# CONFIG_FB_TFT_HX8357D is not set
-# CONFIG_FB_TFT_ILI9163 is not set
-# CONFIG_FB_TFT_ILI9320 is not set
-# CONFIG_FB_TFT_ILI9325 is not set
-# CONFIG_FB_TFT_ILI9340 is not set
-# CONFIG_FB_TFT_ILI9341 is not set
-# CONFIG_FB_TFT_ILI9481 is not set
-# CONFIG_FB_TFT_ILI9486 is not set
-# CONFIG_FB_TFT_PCD8544 is not set
-# CONFIG_FB_TFT_RA8875 is not set
-# CONFIG_FB_TFT_S6D02A1 is not set
-# CONFIG_FB_TFT_S6D1121 is not set
-# CONFIG_FB_TFT_SH1106 is not set
-# CONFIG_FB_TFT_SSD1289 is not set
-# CONFIG_FB_TFT_SSD1305 is not set
-# CONFIG_FB_TFT_SSD1306 is not set
-# CONFIG_FB_TFT_SSD1325 is not set
-# CONFIG_FB_TFT_SSD1331 is not set
-# CONFIG_FB_TFT_SSD1351 is not set
-# CONFIG_FB_TFT_ST7735R is not set
-# CONFIG_FB_TFT_ST7789V is not set
-# CONFIG_FB_TFT_TINYLCD is not set
-# CONFIG_FB_TFT_TLS8204 is not set
-# CONFIG_FB_TFT_UC1611 is not set
-# CONFIG_FB_TFT_UC1701 is not set
-# CONFIG_FB_TFT_UPD161704 is not set
-# CONFIG_FB_TFT_WATTEROTT is not set
-# CONFIG_FB_FLEX is not set
-# CONFIG_FB_TFT_FBTFT_DEVICE is not set
+# CONFIG_FB_TFT is not set
 CONFIG_WILC1000=m
 CONFIG_WILC1000_SDIO=m
 CONFIG_WILC1000_SPI=m
@@ -7728,26 +7697,7 @@ CONFIG_HDM_DIM2=m
 CONFIG_HDM_I2C=m
 CONFIG_HDM_USB=m
 CONFIG_KS7010=m
-CONFIG_GREYBUS=m
-CONFIG_GREYBUS_ES2=m
-CONFIG_GREYBUS_AUDIO=m
-CONFIG_GREYBUS_BOOTROM=m
-CONFIG_GREYBUS_FIRMWARE=m
-CONFIG_GREYBUS_HID=m
-CONFIG_GREYBUS_LIGHT=m
-CONFIG_GREYBUS_LOG=m
-CONFIG_GREYBUS_LOOPBACK=m
-CONFIG_GREYBUS_POWER=m
-CONFIG_GREYBUS_RAW=m
-CONFIG_GREYBUS_VIBRATOR=m
-CONFIG_GREYBUS_BRIDGED_PHY=m
-CONFIG_GREYBUS_GPIO=m
-CONFIG_GREYBUS_I2C=m
-CONFIG_GREYBUS_PWM=m
-CONFIG_GREYBUS_SDIO=m
-CONFIG_GREYBUS_SPI=m
-CONFIG_GREYBUS_UART=m
-CONFIG_GREYBUS_USB=m
+# CONFIG_GREYBUS is not set
 CONFIG_CRYPTO_DEV_CCREE=m
 
 #
@@ -7874,6 +7824,7 @@ CONFIG_HWSPINLOCK=y
 # Clock Source drivers
 #
 CONFIG_CLKEVT_I8253=y
+CONFIG_I8253_LOCK=y
 CONFIG_CLKBLD_I8253=y
 # CONFIG_ATMEL_PIT is not set
 # CONFIG_SH_TIMER_CMT is not set
@@ -8995,6 +8946,7 @@ CONFIG_SCHED_INFO=y
 CONFIG_SCHEDSTATS=y
 CONFIG_SCHED_STACK_END_CHECK=y
 # CONFIG_DEBUG_TIMEKEEPING is not set
+CONFIG_DEBUG_PREEMPT=y
 
 #
 # Lock Debugging (spinlocks, mutexes, etc...)
@@ -9060,6 +9012,7 @@ CONFIG_FUNCTION_TRACER=y
 CONFIG_FUNCTION_GRAPH_TRACER=y
 # CONFIG_PREEMPTIRQ_EVENTS is not set
 # CONFIG_IRQSOFF_TRACER is not set
+# CONFIG_PREEMPT_TRACER is not set
 CONFIG_SCHED_TRACER=y
 CONFIG_HWLAT_TRACER=y
 CONFIG_FTRACE_SYSCALLS=y