On 8/22/2025 12:45 PM, Greg KH wrote:
On Fri, Aug 22, 2025 at 10:01:58AM +0800, William Wu wrote:
If the hid transfer with size divisible to EPs max packet
size, it needs to set the req->zero to true, then the usb
controller can transfer a zero length packet at the end
according to the USB 2.0 spec.
Signed-off-by: William Wu <william.wu@xxxxxxxxxxxxxx>
---
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..8021af3 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 = ((count % hidg->in_ep->maxpacket) == 0);
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 = ((length % cdev->gadget->ep0->maxpacket) == 0);
req->length = length;
status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
if (status < 0)
What commit id does this fix?
It seems that the first verison of the f_hid.c had this issue.
commit 71adf1189469 ("USB: gadget: add HID gadget driver")
Best Regards,
William Wu>
thanks,
greg k-h
