[PATCH 5.15 027/177] usb: cdns3: Fix issue for clear halt endpoint

Greg Kroah-Hartman
2022-05-04T17:22:18Z

From: Pawel Laszczak <pawell@cadence.com>

commit b3fa25de31fb7e9afebe9599b8ff32eda13d7c94 upstream.

Path fixes bug which occurs during resetting endpoint in
__cdns3_gadget_ep_clear_halt function. During resetting endpoint
controller will change HW/DMA owned TRB. It set Abort flag in
trb->control and will change trb->length field. If driver want
to use the aborted trb it must update the changed field in
TRB.

Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
cc: <stable@vger.kernel.org>
Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Link: https://lore.kernel.org/r/20220329084605.4022-1-pawell@cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/cdns3/cdns3-gadget.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2684,6 +2684,7 @@ int __cdns3_gadget_ep_clear_halt(struct
struct usb_request *request;
struct cdns3_request *priv_req;
struct cdns3_trb *trb = NULL;
+ struct cdns3_trb trb_tmp;
int ret;
int val;

@@ -2693,8 +2694,10 @@ int __cdns3_gadget_ep_clear_halt(struct
if (request) {
priv_req = to_cdns3_request(request);
trb = priv_req->trb;
- if (trb)
+ if (trb) {
+ trb_tmp = *trb;
trb->control = trb->control ^ cpu_to_le32(TRB_CYCLE);
+ }
}

writel(EP_CMD_CSTALL | EP_CMD_EPRST, &priv_dev->regs->ep_cmd);
@@ -2709,7 +2712,7 @@ int __cdns3_gadget_ep_clear_halt(struct

if (request) {
if (trb)
- trb->control = trb->control ^ cpu_to_le32(TRB_CYCLE);
+ *trb = trb_tmp;

cdns3_rearm_transfer(priv_ep, 1);
}