In ISOC transfers, when free_slot points to the last TRB (i.e. Link TRB), and all queued requests meet Missed Interval Isoc error, busy_slot points to trb0. busy_slot->trb0 trb1 ... free_slot->trb31(Link TRB) After end transfer and receiving the XferNotReady event, trb_left is caculated as 1 which is wrong, and no TRB will be primed to the endpoint. The root cause is free_slot is not increased the same way as busy_slot. When busy_slot is increased by one, it checks if points to a link TRB after increasement, but free_slot checks it before increasement. free_slot should behave the same as busy_slot to make the trb_left caculation correct. Signed-off-by: Zhuang Jin Can <jin.can.zhuang@xxxxxxxxx> Signed-off-by: Jiebing Li <jiebing.li@xxxxxxxxx> --- drivers/usb/dwc3/gadget.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 54da8c8..2ebe82b 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -828,10 +828,6 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep, length, last ? " last" : "", chain ? " chain" : ""); - /* Skip the LINK-TRB on ISOC */ - if (((dep->free_slot & DWC3_TRB_MASK) == DWC3_TRB_NUM - 1) && - usb_endpoint_xfer_isoc(dep->endpoint.desc)) - dep->free_slot++; trb = &dep->trb_pool[dep->free_slot & DWC3_TRB_MASK]; @@ -843,6 +839,10 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep, } dep->free_slot++; + /* Skip the LINK-TRB on ISOC */ + if (((dep->free_slot & DWC3_TRB_MASK) == DWC3_TRB_NUM - 1) && + usb_endpoint_xfer_isoc(dep->endpoint.desc)) + dep->free_slot++; trb->size = DWC3_TRB_SIZE_LENGTH(length); trb->bpl = lower_32_bits(dma); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
