diff --git a/lib/cpus/aarch32/cortex_a17.S b/lib/cpus/aarch32/cortex_a17.S
index b84c126..87e8c8d 100644
--- a/lib/cpus/aarch32/cortex_a17.S
+++ b/lib/cpus/aarch32/cortex_a17.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -35,6 +35,34 @@
 	bx	lr
 endfunc cortex_a17_enable_smp
 
+	/* ----------------------------------------------------
+	 * Errata Workaround for Cortex A17 Errata #852421.
+	 * This applies only to revision <= r1p2 of Cortex A17.
+	 * Inputs:
+	 * r0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: r0-r3
+	 * ----------------------------------------------------
+	 */
+func errata_a17_852421_wa
+	/*
+	 * Compare r0 against revision r1p2
+	 */
+	mov	r2, lr
+	bl	check_errata_852421
+	cmp	r0, #ERRATA_NOT_APPLIES
+	beq	1f
+	ldcopr	r0, CORTEX_A17_IMP_DEF_REG1
+	orr	r0, r0, #(1<<24)
+	stcopr	r0, CORTEX_A17_IMP_DEF_REG1
+1:
+	bx	r2
+endfunc errata_a17_852421_wa
+
+func check_errata_852421
+	mov	r1, #0x12
+	b	cpu_rev_var_ls
+endfunc check_errata_852421
+
 func check_errata_cve_2017_5715
 #if WORKAROUND_CVE_2017_5715
 	mov	r0, #ERRATA_APPLIES
@@ -58,6 +86,7 @@
 	 * Report all errata. The revision-variant information is passed to
 	 * checking functions of each errata.
 	 */
+	report_errata ERRATA_A17_852421, cortex_a17, 852421
 	report_errata WORKAROUND_CVE_2017_5715, cortex_a17, cve_2017_5715
 
 	pop	{r12, lr}
@@ -66,12 +95,21 @@
 #endif
 
 func cortex_a17_reset_func
+	mov	r5, lr
+	bl	cpu_get_rev_var
+
+#if ERRATA_A17_852421
+	bl	errata_a17_852421_wa
+#endif
+
 #if IMAGE_BL32 && WORKAROUND_CVE_2017_5715
 	ldr	r0, =workaround_bpiall_runtime_exceptions
 	stcopr	r0, VBAR
 	stcopr	r0, MVBAR
 	/* isb will be applied in the course of the reset func */
 #endif
+
+	mov	lr, r5
 	b	cortex_a17_enable_smp
 endfunc cortex_a17_reset_func
 
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index f178f1a..9ccd787 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -61,6 +61,10 @@
 # only to revision >= r3p0 of the Cortex A15 cpu.
 ERRATA_A15_827671	?=0
 
+# Flag to apply erratum 852421 workaround during reset. This erratum applies
+# only to revision <= r1p2 of the Cortex A17 cpu.
+ERRATA_A17_852421	?=0
+
 # Flag to apply erratum 819472 workaround during reset. This erratum applies
 # only to revision <= r0p1 of the Cortex A53 cpu.
 ERRATA_A53_819472	?=0
@@ -212,6 +216,10 @@
 $(eval $(call assert_boolean,ERRATA_A15_827671))
 $(eval $(call add_define,ERRATA_A15_827671))
 
+# Process ERRATA_A17_852421 flag
+$(eval $(call assert_boolean,ERRATA_A17_852421))
+$(eval $(call add_define,ERRATA_A17_852421))
+
 # Process ERRATA_A53_819472 flag
 $(eval $(call assert_boolean,ERRATA_A53_819472))
 $(eval $(call add_define,ERRATA_A53_819472))