[PATCH v2] usb: xhci: Check the return value from sg_pcopy_from_buffer

[Zhihao Cheng]

Fix the following gcc warning:

drivers/usb/host/xhci.c:1349:15: warning: variable ‘len’ set but not
used [-Wunused-but-set-variable ]

Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
---
 drivers/usb/host/xhci.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index ca9385d22f68..08290698b939 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1361,11 +1361,15 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)
 				 urb->transfer_buffer_length,
 				 dir);
 
-	if (usb_urb_dir_in(urb))
+	if (usb_urb_dir_in(urb)) {
 		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,
 					   urb->transfer_buffer,
 					   buf_len,
 					   0);
+		if (len != buf_len)
+			xhci_warn(hcd_to_xhci(hcd), "WARN Wrong transfer buffer read length: %u != %u\n",
+				  len, buf_len);
+	}
 
 	urb->transfer_flags &= ~URB_DMA_MAP_SINGLE;
 	kfree(urb->transfer_buffer);
-- 
2.25.4