diff mbox series

[4/5] usb: isp1760: do not shift in uninitialized slot

Message ID 20210819180929.1327349-5-rui.silva@linaro.org (mailing list archive)
State Accepted
Commit 7d1d3882fd9da1ee42fe3ad3a5ffd41fb8204380
Headers show
Series usb: isp1760: clang analyzer fixes | expand

Commit Message

Rui Miguel Silva Aug. 19, 2021, 6:09 p.m. UTC 
Even though it is not expected, and would trigger a WARN_ON, killing a
transfer in a uninitialized slot this sequence is warned by clang
analyzer, twice:

drivers/usb/isp1760/isp1760-hcd.c:1976:18: warning: The result of the left shift is undefined because the right operand is negative [clang-analyzer-core.UndefinedBinaryOperatorResult]
                skip_map |= (1 << qh->slot);
drivers/usb/isp1760/isp1760-hcd.c:1983:18: warning: The result of the left shift is undefined because the right operand is negative [clang-analyzer-core.UndefinedBinaryOperatorResult]
                skip_map |= (1 << qh->slot);

Only set skip map if slot is active.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 drivers/usb/isp1760/isp1760-hcd.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/isp1760/isp1760-hcd.c b/drivers/usb/isp1760/isp1760-hcd.c
index aed2714ce0cf..bf8ab3fe2e5a 100644
--- a/drivers/usb/isp1760/isp1760-hcd.c
+++ b/drivers/usb/isp1760/isp1760-hcd.c
@@ -1974,16 +1974,20 @@  static void kill_transfer(struct usb_hcd *hcd, struct urb *urb,
 	/* We need to forcefully reclaim the slot since some transfers never
 	   return, e.g. interrupt transfers and NAKed bulk transfers. */
 	if (usb_pipecontrol(urb->pipe) || usb_pipebulk(urb->pipe)) {
-		skip_map = isp1760_hcd_read(hcd, HC_ATL_PTD_SKIPMAP);
-		skip_map |= (1 << qh->slot);
-		isp1760_hcd_write(hcd, HC_ATL_PTD_SKIPMAP, skip_map);
-		ndelay(100);
+		if (qh->slot != -1) {
+			skip_map = isp1760_hcd_read(hcd, HC_ATL_PTD_SKIPMAP);
+			skip_map |= (1 << qh->slot);
+			isp1760_hcd_write(hcd, HC_ATL_PTD_SKIPMAP, skip_map);
+			ndelay(100);
+		}
 		priv->atl_slots[qh->slot].qh = NULL;
 		priv->atl_slots[qh->slot].qtd = NULL;
 	} else {
-		skip_map = isp1760_hcd_read(hcd, HC_INT_PTD_SKIPMAP);
-		skip_map |= (1 << qh->slot);
-		isp1760_hcd_write(hcd, HC_INT_PTD_SKIPMAP, skip_map);
+		if (qh->slot != -1) {
+			skip_map = isp1760_hcd_read(hcd, HC_INT_PTD_SKIPMAP);
+			skip_map |= (1 << qh->slot);
+			isp1760_hcd_write(hcd, HC_INT_PTD_SKIPMAP, skip_map);
+		}
 		priv->int_slots[qh->slot].qh = NULL;
 		priv->int_slots[qh->slot].qtd = NULL;
 	}