Ignore:
Timestamp:
2018-01-10T00:46:29Z (7 years ago)
Author:
Ondřej Hlavatý <aearsis@…>
Branches:
lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export
Children:
f92f6b1
Parents:
4793023
git-author:
Ondřej Hlavatý <aearsis@…> (2018-01-09 19:26:55)
git-committer:
Ondřej Hlavatý <aearsis@…> (2018-01-10 00:46:29)
Message:

xhci: rewritten isochronous transfers

There was a fundamental problem with relying on hardware to send
RING_OVERRUN/UNDERRUN events, which QEMU (and possibly others) do not
send. That resulted in not knowing if the transfer is still on schedule,
and having to ring the doorbell every time. That is not feasible,
because then the transfer can be more frequent than it should be.
Furthermore, it ignored the fact that isochronous TRBs are to be
scheduled not too late, but also not too soon (see 4.11.2.5 of the xHCI
spec).

Now, scheduling the TRBs to hardware is called feeding, and can be
delayed by setting a timer. Ring overruns/underruns are detected also at
the end of handling an event.

File:
1 edited

Legend:

Unmodified
Added
Removed
  • uspace/drv/bus/usb/xhci/hw_struct/trb.h

    r4793023 r708d8fcd  
    147147        xhci_dword_set_bits(&(trb).control, val, 17, 16)
    148148
    149 #define TRB_CTRL_SET_TBC(trb, val) \
     149#define TRB_ISOCH_SET_TBC(trb, val) \
    150150        xhci_dword_set_bits(&(trb).control, val, 8, 7)
    151 #define TRB_CTRL_SET_TLBPC(trb, val) \
     151#define TRB_ISOCH_SET_TLBPC(trb, val) \
    152152        xhci_dword_set_bits(&(trb).control, val, 19, 16)
    153 #define TRB_CTRL_SET_SIA(trb, val) \
     153#define TRB_ISOCH_SET_FRAMEID(trb, val) \
     154        xhci_dword_set_bits(&(trb).control, val, 30, 20)
     155#define TRB_ISOCH_SET_SIA(trb, val) \
    154156        xhci_dword_set_bits(&(trb).control, val, 31, 31)
    155157
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