From ed6f727c575b1eb8136e744acfd5e7306c9548f6 Mon Sep 17 00:00:00 2001 From: William Wu Date: Tue, 26 Aug 2025 18:28:07 +0800 Subject: [PATCH] usb: gadget: f_hid: Fix zero length packet transfer 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 Link: https://lore.kernel.org/r/1756204087-26111-1-git-send-email-william.wu@rock-chips.com Signed-off-by: Greg Kroah-Hartman --- 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 8e1d1e884050..307ea563af95 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -511,7 +511,7 @@ try_again: } 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 @@ stall: 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) -- 2.47.3