Per dwc3 2.50a spec, the is_devspec bit is used to distinguish the Device Endpoint-Specific Event or Device-Specific Event (DEVT). If the bit is 1, the event is represented Device-Specific Event, then use [7:1] bits as Device Specific Event to marked the type. It has 7 bits, and we can see the reserved8_31 variable name which means from 8 to 31 bits marked reserved, actually there are 24 bits not 25 bits between that. And 1 + 7 + 24 = 32, the event size is 4 byes.
So in dwc3_event_type, the bit mask should be: is_devspec [0] 1 bit type [7:1] 7 bits reserved8_31 [31:8] 24 bits This patch should be backported to kernels as old as 3.2, that contain the commit 72246da40f3719af3bfd104a2365b32537c27d83 "usb: Introduce DesignWare USB3 DRD Driver". Signed-off-by: Huang Rui <ray.hu...@amd.com> Cc: sta...@vger.kernel.org --- drivers/usb/dwc3/core.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index c4b5127..00a72e3 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -758,8 +758,8 @@ struct dwc3 { struct dwc3_event_type { u32 is_devspec:1; - u32 type:6; - u32 reserved8_31:25; + u32 type:7; + u32 reserved8_31:24; } __packed; #define DWC3_DEPEVT_XFERCOMPLETE 0x01 -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html