Re: A RPi4 xHCI VL805 problem that needs to be avoided: "xhci: quirks: add link TRB quirk for VL805"
Hans Petter Selasky <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.arm |
|---|---|
| Message-ID | <[email protected]> |
On 2020-10-27 00:58, Mark Millard via freebsd-arm wrote: > https://github.com/raspberrypi/linux/pull/3929 reports: > > QUOTE > The VL805 controller can't cope with the TR Dequeue Pointer for an endpoint > being set to a Link TRB. The hardware-maintained endpoint context ends up > stuck at the address of the Link TRB, leading to erroneous ring expansion > events whenever the enqueue pointer wraps to the dequeue position. > > If the search for the end of the current TD and ring cycle state lands on > a Link TRB, move to the next segment. > END QUOTE > > Also: Dealing with the link trb also toggling the ring cycle state > is something to watch for according to the later notes. > Is this an issue under FreeBSD too? Can it be reproduced? --HPS _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-arm To unsubscribe, send any mail to "[email protected]"