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authorPawel Laszczak <pawell@cadence.com>2024-08-21 06:07:42 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-09-04 13:25:04 +0200
commitb4ecded1460378ea0b2acba91d72f1a5e470f57a (patch)
tree2723176fa612acc525f5c6c28fa7e3a146e6d823
parentd0a0a4b407820e89d6355364d30092ad31eb30fa (diff)
usb: cdnsp: fix for Link TRB with TC
commit 740f2e2791b98e47288b3814c83a3f566518fed2 upstream. Stop Endpoint command on LINK TRB with TC bit set to 1 causes that internal cycle bit can have incorrect state after command complete. In consequence empty transfer ring can be incorrectly detected when EP is resumed. NOP TRB before LINK TRB avoid such scenario. Stop Endpoint command is then on NOP TRB and internal cycle bit is not changed and have correct value. Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver") cc: <stable@vger.kernel.org> Signed-off-by: Pawel Laszczak <pawell@cadence.com> Reviewed-by: Peter Chen <peter.chen@kernel.org> Link: https://lore.kernel.org/r/PH7PR07MB953878279F375CCCE6C6F40FDD8E2@PH7PR07MB9538.namprd07.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/cdns3/cdnsp-gadget.h3
-rw-r--r--drivers/usb/cdns3/cdnsp-ring.c28
2 files changed, 31 insertions, 0 deletions
diff --git a/drivers/usb/cdns3/cdnsp-gadget.h b/drivers/usb/cdns3/cdnsp-gadget.h
index f740fa6089d8..a61aef0dc273 100644
--- a/drivers/usb/cdns3/cdnsp-gadget.h
+++ b/drivers/usb/cdns3/cdnsp-gadget.h
@@ -811,6 +811,7 @@ struct cdnsp_stream_info {
* generate Missed Service Error Event.
* Set skip flag when receive a Missed Service Error Event and
* process the missed tds on the endpoint ring.
+ * @wa1_nop_trb: hold pointer to NOP trb.
*/
struct cdnsp_ep {
struct usb_ep endpoint;
@@ -838,6 +839,8 @@ struct cdnsp_ep {
#define EP_UNCONFIGURED BIT(7)
bool skip;
+ union cdnsp_trb *wa1_nop_trb;
+
};
/**
diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c
index bc4483f408d3..04e8db773a82 100644
--- a/drivers/usb/cdns3/cdnsp-ring.c
+++ b/drivers/usb/cdns3/cdnsp-ring.c
@@ -1903,6 +1903,23 @@ int cdnsp_queue_bulk_tx(struct cdnsp_device *pdev, struct cdnsp_request *preq)
return ret;
/*
+ * workaround 1: STOP EP command on LINK TRB with TC bit set to 1
+ * causes that internal cycle bit can have incorrect state after
+ * command complete. In consequence empty transfer ring can be
+ * incorrectly detected when EP is resumed.
+ * NOP TRB before LINK TRB avoid such scenario. STOP EP command is
+ * then on NOP TRB and internal cycle bit is not changed and have
+ * correct value.
+ */
+ if (pep->wa1_nop_trb) {
+ field = le32_to_cpu(pep->wa1_nop_trb->trans_event.flags);
+ field ^= TRB_CYCLE;
+
+ pep->wa1_nop_trb->trans_event.flags = cpu_to_le32(field);
+ pep->wa1_nop_trb = NULL;
+ }
+
+ /*
* Don't give the first TRB to the hardware (by toggling the cycle bit)
* until we've finished creating all the other TRBs. The ring's cycle
* state may change as we enqueue the other TRBs, so save it too.
@@ -1997,6 +2014,17 @@ int cdnsp_queue_bulk_tx(struct cdnsp_device *pdev, struct cdnsp_request *preq)
send_addr = addr;
}
+ if (cdnsp_trb_is_link(ring->enqueue + 1)) {
+ field = TRB_TYPE(TRB_TR_NOOP) | TRB_IOC;
+ if (!ring->cycle_state)
+ field |= TRB_CYCLE;
+
+ pep->wa1_nop_trb = ring->enqueue;
+
+ cdnsp_queue_trb(pdev, ring, 0, 0x0, 0x0,
+ TRB_INTR_TARGET(0), field);
+ }
+
cdnsp_check_trb_math(preq, enqd_len);
ret = cdnsp_giveback_first_trb(pdev, pep, preq->request.stream_id,
start_cycle, start_trb);