diff --git a/drivers/usb/cdns3/cdnsp-gadget.c b/drivers/usb/cdns3/cdnsp-gadget.c index 601a60a28022..1ef7ee5a47c7 100644 --- a/drivers/usb/cdns3/cdnsp-gadget.c +++ b/drivers/usb/cdns3/cdnsp-gadget.c @@ -546,6 +546,7 @@ 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; @@ -577,8 +578,23 @@ 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);