Pawel, with your change, the TD_SIZE is 1 or 0, but not like the kernel doc defined like below:
Please omit my comments, I did not check the code carefully.
/*
- TD size is the number of max packet sized packets remaining in the
TD
- (*not* including this TRB).
With your current change, it may work. But your change conflicts with the xHCI spec that described above. With ZLP, the last useful trb's TD size should be 0, but if it is 0, the controller will be confused.
With your change, it makes the code more different with xhci's. Do you consider handling ZLP packet at another TD instead of current at the same TD ？
Yes, I considered it, but to simplify the driver I resigned from handling multiple TD per usb_request. Current solution is simpler and supported by device controller.
Additionally, the next ZLP fix must be added for control endpoint for Data Stage and probably it will not work with 2 TDs.
Pawel
- Total TD packet count = total_packet_count =
DIV_ROUND_UP(TD size in bytes / wMaxPacketSize)- Packets transferred up to and including this TRB = packets_transferred =
rounddown(total bytes transferred including this TRB /wMaxPacketSize)
- TD size = total_packet_count - packets_transferred
- It must fit in bits 21:17, so it can't be bigger than 31.
- This is taken care of in the TRB_TD_SIZE() macro
- The last TRB in a TD must have the TD size set to zero.
*/
Peter
/* One TRB with a zero-length data packet. */ if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) || trb_buff_len == td_total_len) @@ -1960,7 +1965,8 @@ intcdnsp_queue_bulk_tx(struct cdnsp_device *pdev, struct cdnsp_request
*preq)
/* Set the TRB length, TD size, and interrupter fields. */ remainder = cdnsp_td_remainder(pdev, enqd_len, trb_buff_len, full_len, preq,
more_trbs_coming);
more_trbs_coming,zero_len_trb); length_field = TRB_LEN(trb_buff_len) | TRB_TD_SIZE(remainder)|
TRB_INTR_TARGET(0); @@ -2025,7 +2031,7 @@int cdnsp_queue_ctrl_tx(struct cdnsp_device *pdev, struct cdnsp_request *preq)
if (preq->request.length > 0) { remainder = cdnsp_td_remainder(pdev, 0, preq->request.length,
preq->request.length, preq, 1);
preq->request.length,preq, 1, 0);
length_field = TRB_LEN(preq->request.length) | TRB_TD_SIZE(remainder) |TRB_INTR_TARGET(0); @@ -2225,7 +2231,7 @@ static int
cdnsp_queue_isoc_tx(struct cdnsp_device *pdev,
/* Set the TRB length, TD size, & interrupter fields. */ remainder = cdnsp_td_remainder(pdev, running_total, trb_buff_len, td_len, preq,
more_trbs_coming);
more_trbs_coming, 0); length_field = TRB_LEN(trb_buff_len) |TRB_INTR_TARGET(0);
-- 2.25.1