[PATCH 5.15 711/731] xhci: Prevent infinite loop in transaction errors recovery for streams

Greg Kroah-Hartman
2022-12-28T16:02:26Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

commit a1575120972ecd7baa6af6a69e4e7ea9213bde7c upstream.

Make sure to also limit the amount of soft reset retries for transaction
errors on streams in cases where the transaction error event doesn't point
to any specific TRB.

In these cases we don't know the TRB or stream ring, but we do know which
endpoint had the error.

To keep error counting simple and functional, move the current err_count
from ring structure to endpoint structure.

Cc: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20221130091944.2171610-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/host/xhci-ring.c | 14 ++++++++++----
drivers/usb/host/xhci.h | 2 +-
2 files changed, 11 insertions(+), 5 deletions(-)

--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2524,7 +2524,7 @@ static int process_bulk_intr_td(struct x

switch (trb_comp_code) {
case COMP_SUCCESS:
- ep_ring->err_count = 0;
+ ep->err_count = 0;
/* handle success with untransferred data as short packet */
if (ep_trb != td->last_trb || remaining) {
xhci_warn(xhci, "WARN Successful completion on short TX\n");
@@ -2550,7 +2550,7 @@ static int process_bulk_intr_td(struct x
break;
case COMP_USB_TRANSACTION_ERROR:
if (xhci->quirks & XHCI_NO_SOFT_RETRY ||
- (ep_ring->err_count++ > MAX_SOFT_RETRY) ||
+ (ep->err_count++ > MAX_SOFT_RETRY) ||
le32_to_cpu(slot_ctx->tt_info) & TT_SLOT)
break;

@@ -2631,8 +2631,14 @@ static int handle_tx_event(struct xhci_h
case COMP_USB_TRANSACTION_ERROR:
case COMP_INVALID_STREAM_TYPE_ERROR:
case COMP_INVALID_STREAM_ID_ERROR:
- xhci_handle_halted_endpoint(xhci, ep, 0, NULL,
- EP_SOFT_RESET);
+ xhci_dbg(xhci, "Stream transaction error ep %u no id\n",
+ ep_index);
+ if (ep->err_count++ > MAX_SOFT_RETRY)
+ xhci_handle_halted_endpoint(xhci, ep, 0, NULL,
+ EP_HARD_RESET);
+ else
+ xhci_handle_halted_endpoint(xhci, ep, 0, NULL,
+ EP_SOFT_RESET);
goto cleanup;
case COMP_RING_UNDERRUN:
case COMP_RING_OVERRUN:
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -933,6 +933,7 @@ struct xhci_virt_ep {
* have to restore the device state to the previous state
*/
struct xhci_ring *new_ring;
+ unsigned int err_count;
unsigned int ep_state;
#define SET_DEQ_PENDING (1 << 0)
#define EP_HALTED (1 << 1) /* For stall handling */
@@ -1629,7 +1630,6 @@ struct xhci_ring {
* if we own the TRB (if we are the consumer). See section 4.9.1.
*/
u32 cycle_state;
- unsigned int err_count;
unsigned int stream_id;
unsigned int num_segs;
unsigned int num_trbs_free;