diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 4653efb87a27..6804d474a47d 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -139,6 +139,8 @@
 #include <linux/slab.h>
 #include <linux/bootmem.h>
 
+#include <asm/system_misc.h>
+
 #include "clock.h"
 #include "omap_hwmod.h"
 
@@ -2134,6 +2136,8 @@ static int _enable(struct omap_hwmod *oh)
 	_enable_clocks(oh);
 	if (soc_ops.enable_module)
 		soc_ops.enable_module(oh);
+	if (oh->flags & HWMOD_BLOCK_WFI)
+		disable_hlt();
 
 	if (soc_ops.update_context_lost)
 		soc_ops.update_context_lost(oh);
@@ -2195,6 +2199,8 @@ static int _idle(struct omap_hwmod *oh)
 		_idle_sysc(oh);
 	_del_initiator_dep(oh, mpu_oh);
 
+	if (oh->flags & HWMOD_BLOCK_WFI)
+		enable_hlt();
 	if (soc_ops.disable_module)
 		soc_ops.disable_module(oh);
 
@@ -2303,6 +2309,8 @@ static int _shutdown(struct omap_hwmod *oh)
 	if (oh->_state == _HWMOD_STATE_ENABLED) {
 		_del_initiator_dep(oh, mpu_oh);
 		/* XXX what about the other system initiators here? dma, dsp */
+		if (oh->flags & HWMOD_BLOCK_WFI)
+			enable_hlt();
 		if (soc_ops.disable_module)
 			soc_ops.disable_module(oh);
 		_disable_clocks(oh);
diff --git a/arch/arm/mach-omap2/omap_hwmod.h b/arch/arm/mach-omap2/omap_hwmod.h
index 3ae852a522f9..80c00e706d69 100644
--- a/arch/arm/mach-omap2/omap_hwmod.h
+++ b/arch/arm/mach-omap2/omap_hwmod.h
@@ -451,6 +451,14 @@ struct omap_hwmod_omap4_prcm {
  *     enabled.  This prevents the hwmod code from being able to
  *     enable and reset the IP block early.  XXX Eventually it should
  *     be possible to query the clock framework for this information.
+ * HWMOD_BLOCK_WFI: Some OMAP peripherals apparently don't work
+ *     correctly if the MPU is allowed to go idle while the
+ *     peripherals are active.  This is apparently true for the I2C on
+ *     OMAP2420, and also the EMAC on AM3517/3505.  It's unlikely that
+ *     this is really true -- we're probably not configuring something
+ *     correctly, or this is being abused to deal with some PM latency
+ *     issues -- but we're currently suffering from a shortage of
+ *     folks who are able to track these issues down properly.
  */
 #define HWMOD_SWSUP_SIDLE			(1 << 0)
 #define HWMOD_SWSUP_MSTANDBY			(1 << 1)
@@ -462,6 +470,7 @@ struct omap_hwmod_omap4_prcm {
 #define HWMOD_CONTROL_OPT_CLKS_IN_RESET		(1 << 7)
 #define HWMOD_16BIT_REG				(1 << 8)
 #define HWMOD_EXT_OPT_MAIN_CLK			(1 << 9)
+#define HWMOD_BLOCK_WFI				(1 << 10)
 
 /*
  * omap_hwmod._int_flags definitions