Index: head/sys/dev/sfxge/common/efx_impl.h
===================================================================
--- head/sys/dev/sfxge/common/efx_impl.h
+++ head/sys/dev/sfxge/common/efx_impl.h
@@ -536,7 +536,8 @@
 	__in			uint32_t partn,
 	__out_opt		size_t *sizep,
 	__out_opt		uint32_t *addressp,
-	__out_opt		uint32_t *erase_sizep);
+	__out_opt		uint32_t *erase_sizep,
+	__out_opt		uint32_t *write_sizep);
 
 	__checkReturn		efx_rc_t
 efx_mcdi_nvram_update_start(
Index: head/sys/dev/sfxge/common/efx_nvram.c
===================================================================
--- head/sys/dev/sfxge/common/efx_nvram.c
+++ head/sys/dev/sfxge/common/efx_nvram.c
@@ -567,10 +567,11 @@
 	__in			uint32_t partn,
 	__out_opt		size_t *sizep,
 	__out_opt		uint32_t *addressp,
-	__out_opt		uint32_t *erase_sizep)
+	__out_opt		uint32_t *erase_sizep,
+	__out_opt		uint32_t *write_sizep)
 {
 	uint8_t payload[MAX(MC_CMD_NVRAM_INFO_IN_LEN,
-			    MC_CMD_NVRAM_INFO_OUT_LEN)];
+			    MC_CMD_NVRAM_INFO_V2_OUT_LEN)];
 	efx_mcdi_req_t req;
 	efx_rc_t rc;
 
@@ -579,7 +580,7 @@
 	req.emr_in_buf = payload;
 	req.emr_in_length = MC_CMD_NVRAM_INFO_IN_LEN;
 	req.emr_out_buf = payload;
-	req.emr_out_length = MC_CMD_NVRAM_INFO_OUT_LEN;
+	req.emr_out_length = MC_CMD_NVRAM_INFO_V2_OUT_LEN;
 
 	MCDI_IN_SET_DWORD(req, NVRAM_INFO_IN_TYPE, partn);
 
@@ -604,6 +605,13 @@
 	if (erase_sizep)
 		*erase_sizep = MCDI_OUT_DWORD(req, NVRAM_INFO_OUT_ERASESIZE);
 
+	if (write_sizep) {
+		*write_sizep =
+			(req.emr_out_length_used <
+			    MC_CMD_NVRAM_INFO_V2_OUT_LEN) ?
+			0 : MCDI_OUT_DWORD(req, NVRAM_INFO_V2_OUT_WRITESIZE);
+	}
+
 	return (0);
 
 fail2:
Index: head/sys/dev/sfxge/common/hunt_nvram.c
===================================================================
--- head/sys/dev/sfxge/common/hunt_nvram.c
+++ head/sys/dev/sfxge/common/hunt_nvram.c
@@ -1295,7 +1295,8 @@
 {
 	efx_rc_t rc;
 
-	if ((rc = efx_mcdi_nvram_info(enp, partn, sizep, NULL, NULL)) != 0)
+	if ((rc = efx_mcdi_nvram_info(enp, partn, sizep,
+	    NULL, NULL, NULL)) != 0)
 		goto fail1;
 
 	return (0);
Index: head/sys/dev/sfxge/common/hunt_vpd.c
===================================================================
--- head/sys/dev/sfxge/common/hunt_vpd.c
+++ head/sys/dev/sfxge/common/hunt_vpd.c
@@ -113,7 +113,7 @@
 	 * which is the size of the DYNAMIC_CONFIG partition.
 	 */
 	if ((rc = efx_mcdi_nvram_info(enp, NVRAM_PARTITION_TYPE_DYNAMIC_CONFIG,
-		    sizep, NULL, NULL)) != 0)
+		    sizep, NULL, NULL, NULL)) != 0)
 		goto fail1;
 
 	return (0);
Index: head/sys/dev/sfxge/common/siena_nvram.c
===================================================================
--- head/sys/dev/sfxge/common/siena_nvram.c
+++ head/sys/dev/sfxge/common/siena_nvram.c
@@ -54,7 +54,8 @@
 		goto fail1;
 	}
 
-	if ((rc = efx_mcdi_nvram_info(enp, partn, sizep, NULL, NULL)) != 0) {
+	if ((rc = efx_mcdi_nvram_info(enp, partn, sizep,
+	    NULL, NULL, NULL)) != 0) {
 		goto fail2;
 	}