Changeset 7d1dd2b in mainline for uspace/drv/bus/usb/usbhub/port.h

Timestamp:

2018-01-16T13:36:30Z (7 years ago)

Author:

Ondřej Hlavatý <aearsis@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

47e9494

Parents:

c952abc4

git-author:

Ondřej Hlavatý <aearsis@…> (2018-01-16 13:36:28)

git-committer:

Ondřej Hlavatý <aearsis@…> (2018-01-16 13:36:30)

Message:

usbhub: port simply cannot inform HC when finalizing

There are three options regarding port finalization with device
connected and enabled:

1) Wait until HC disposes the device. Sorry, no, IPC deadlock, because

if the device is a hub, it will need to use the same connection that
is finalizing the port.

2) Create a fibril to announce this to HC. Yeah, no more deadlock, but

race condition. Host controller will want to clean up after the hub,
and will remove devices connected to it as soon as the unbinding
finishes.

3) If he is doing so… lets leave it up to him? That makes HC spit

a warning, but it's the only correct option then.

(No files)