diff options
| -rw-r--r-- | drivers/usb/gadget/composite.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c index 8e8c3baa9d7e..bdda8c74602d 100644 --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -2111,8 +2111,20 @@ unknown: memset(buf, 0, w_length); buf[5] = 0x01; switch (ctrl->bRequestType & USB_RECIP_MASK) { + /* + * The Microsoft CompatID OS Descriptor Spec(w_index = 0x4) and + * Extended Prop OS Desc Spec(w_index = 0x5) state that the + * HighByte of wValue is the InterfaceNumber and the LowByte is + * the PageNumber. This high/low byte ordering is incorrectly + * documented in the Spec. USB analyzer output on the below + * request packets show the high/low byte inverted i.e LowByte + * is the InterfaceNumber and the HighByte is the PageNumber. + * Since we dont support >64KB CompatID/ExtendedProp descriptors, + * PageNumber is set to 0. Hence verify that the HighByte is 0 + * for below two cases. + */ case USB_RECIP_DEVICE: - if (w_index != 0x4 || (w_value & 0xff)) + if (w_index != 0x4 || (w_value >> 8)) break; buf[6] = w_index; /* Number of ext compat interfaces */ @@ -2128,9 +2140,9 @@ unknown: } break; case USB_RECIP_INTERFACE: - if (w_index != 0x5 || (w_value & 0xff)) + if (w_index != 0x5 || (w_value >> 8)) break; - interface = w_value >> 8; + interface = w_value & 0xFF; if (interface >= MAX_CONFIG_INTERFACES || !os_desc_cfg->interface[interface]) break; |