Ignore:
Timestamp:
2018-01-10T00:46:29Z (6 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/lib/drv/include/usbhc_iface.h

    r4793023 r708d8fcd  
    6464 * Callers shall fill it with bare contents of respective descriptors (in usb endianity).
    6565 */
    66 typedef struct {
     66typedef struct usb_endpoint_descriptors {
    6767        struct {
    6868                uint8_t endpoint_address;
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