Set the hid req->zero flag of ep0/in_ep to true by default, then the UDC drivers can transfer a zero length packet at the end if the hid transfer with size divisible to EPs max packet size according to the USB 2.0 spec. Signed-off-by: William Wu <william.wu@xxxxxxxxxxxxxx> --- Changelog: v2: - set req->zero to 1 instead of check whether the length is divisible by the maxpacket --- drivers/usb/gadget/function/f_hid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 8e1d1e8..307ea56 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -511,7 +511,7 @@ static ssize_t f_hidg_write(struct file *file, const char __user *buffer, } req->status = 0; - req->zero = 0; + req->zero = 1; req->length = count; req->complete = f_hidg_req_complete; req->context = hidg; @@ -967,7 +967,7 @@ static int hidg_setup(struct usb_function *f, return -EOPNOTSUPP; respond: - req->zero = 0; + req->zero = 1; req->length = length; status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); if (status < 0) -- 2.0.0