Index: uspace/lib/scsi/include/scsi/spc.h
===================================================================
--- uspace/lib/scsi/include/scsi/spc.h	(revision 8e1a819e63c991eb698215d0afabe2a2b5b1ce48)
+++ uspace/lib/scsi/include/scsi/spc.h	(revision 3f08fd2b9072227f3006fed60b75c6f38e7ac5d9)
@@ -38,4 +38,5 @@
 
 #include <stdint.h>
+#include <str.h>
 
 /** SCSI command codes defined in SCSI-SPC */
@@ -93,4 +94,20 @@
 } scsi_std_inquiry_data_t;
 
+/** Size of struct or union member. */
+#define SCSI_MEMBER_SIZE(type, member) \
+    (sizeof(((type *)0) -> member))
+
+/** Size of string buffer needed to hold converted inquiry vendor string */
+#define SCSI_INQ_VENDOR_STR_BUFSIZE \
+    SPASCII_STR_BUFSIZE(SCSI_MEMBER_SIZE(scsi_std_inquiry_data_t, vendor))
+
+/** Size of string buffer needed to hold converted inquiry product string */
+#define SCSI_INQ_PRODUCT_STR_BUFSIZE \
+    SPASCII_STR_BUFSIZE(SCSI_MEMBER_SIZE(scsi_std_inquiry_data_t, product))
+
+/** Size of string buffer needed to hold converted inquiry revision string */
+#define SCSI_INQ_REVISION_STR_BUFSIZE \
+    SPASCII_STR_BUFSIZE(SCSI_MEMBER_SIZE(scsi_std_inquiry_data_t, revision))
+
 /** Bits in scsi_std_inquiry_data_t.pqual_devtype */
 enum scsi_pqual_devtype_bits {