4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: John Youn <John.Youn@xxxxxxxxxxxx> commit 446fa3a95df1e8b78f25e1babc41e46edd200821 upstream. The SuperspeedPlus Device Capability Descriptor has a variable size depending on the number of sublink speed attributes. This patch adds a macro to calculate that size. The macro takes one argument, the Sublink Speed Attribute Count (SSAC) as reported by the descriptor in bmAttributes[4:0]. See USB 3.1 9.6.2.5, Table 9-19. Signed-off-by: John Youn <johnyoun@xxxxxxxxxxxx> Signed-off-by: Felipe Balbi <balbi@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/uapi/linux/usb/ch9.h | 6 ++++++ 1 file changed, 6 insertions(+) --- a/include/uapi/linux/usb/ch9.h +++ b/include/uapi/linux/usb/ch9.h @@ -906,6 +906,12 @@ struct usb_ptm_cap_descriptor { __u8 bDevCapabilityType; } __attribute__((packed)); +/* + * The size of the descriptor for the Sublink Speed Attribute Count + * (SSAC) specified in bmAttributes[4:0]. + */ +#define USB_DT_USB_SSP_CAP_SIZE(ssac) (16 + ssac * 4) + /*-------------------------------------------------------------------------*/ /* USB_DT_WIRELESS_ENDPOINT_COMP: companion descriptor associated with