1 files changed, 2 insertions, 2 deletions

diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h
index c4c79aa331bd..d5a5caec8fbc 100644
--- a/include/uapi/linux/usb/ch9.h
+++ b/include/uapi/linux/usb/ch9.h
@@ -1077,9 +1077,9 @@ struct usb_ptm_cap_descriptor {
 #define USB_DT_USB_PTM_ID_SIZE          3
 /*
  * The size of the descriptor for the Sublink Speed Attribute Count
- * (SSAC) specified in bmAttributes[4:0].
+ * (SSAC) specified in bmAttributes[4:0]. SSAC is zero-based
  */
-#define USB_DT_USB_SSP_CAP_SIZE(ssac)   (16 + ssac * 4)
+#define USB_DT_USB_SSP_CAP_SIZE(ssac)   (12 + (ssac + 1) * 4)
 
 /*-------------------------------------------------------------------------*/