On 3/7/21 12:25 AM, Greg Kroah-Hartman wrote: > On Sat, Mar 06, 2021 at 08:06:44PM +0800, zhangkun4jr@xxxxxxx wrote: >> From: Zhang Kun <zhangkun@xxxxxxxxxx> >> >> The value assigned to len by sg_pcopy_from_buffer() never used for >> anything, so remove it. >> >> Signed-off-by: Zhang Kun <zhangkun@xxxxxxxxxx> >> --- >> drivers/usb/host/xhci.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c >> index bd27bd670104..6ebda89d476c 100644 >> --- a/drivers/usb/host/xhci.c >> +++ b/drivers/usb/host/xhci.c >> @@ -1335,7 +1335,6 @@ static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd, >> >> static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb) >> { >> - unsigned int len; >> unsigned int buf_len; >> enum dma_data_direction dir; >> >> @@ -1351,7 +1350,7 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb) >> dir); >> >> if (usb_urb_dir_in(urb)) >> - len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs, >> + sg_pcopy_from_buffer(urb->sg, urb->num_sgs, >> urb->transfer_buffer, >> buf_len, >> 0); > > SHouldn't this be checked instead of ignored? > Hi, Greg. Considering your tips I checked sg_pcopy_from_buffer(). it copys data from urb->transfer_buffer to urb->sg, and only returns 0 or the 'number of copied bytes', and seems to has no other exception branchs that need to be checked. So I think it should be ingnored. It may also be that I missed something, if that's the case, please correct me. Thanks, Zhang