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-rw-r--r--drivers/usb/cdns3/cdnsp-gadget.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/usb/cdns3/cdnsp-gadget.c b/drivers/usb/cdns3/cdnsp-gadget.c
index cd1e00daf43f5..55f95f41b3b4d 100644
--- a/drivers/usb/cdns3/cdnsp-gadget.c
+++ b/drivers/usb/cdns3/cdnsp-gadget.c
@@ -548,6 +548,7 @@ int cdnsp_wait_for_cmd_compl(struct cdnsp_device *pdev)
dma_addr_t cmd_deq_dma;
union cdnsp_trb *event;
u32 cycle_state;
+ u32 retry = 10;
int ret, val;
u64 cmd_dma;
u32 flags;
@@ -579,8 +580,23 @@ int cdnsp_wait_for_cmd_compl(struct cdnsp_device *pdev)
flags = le32_to_cpu(event->event_cmd.flags);
/* Check the owner of the TRB. */
- if ((flags & TRB_CYCLE) != cycle_state)
+ if ((flags & TRB_CYCLE) != cycle_state) {
+ /*
+ * Give some extra time to get chance controller
+ * to finish command before returning error code.
+ * Checking CMD_RING_BUSY is not sufficient because
+ * this bit is cleared to '0' when the Command
+ * Descriptor has been executed by controller
+ * and not when command completion event has
+ * be added to event ring.
+ */
+ if (retry--) {
+ udelay(20);
+ continue;
+ }
+
return -EINVAL;
+ }
cmd_dma = le64_to_cpu(event->event_cmd.cmd_trb);