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| author | thompsa <thompsa@FreeBSD.org> | 2009-03-06 17:13:12 +0000 |
|---|---|---|
| committer | thompsa <thompsa@FreeBSD.org> | 2009-03-06 17:13:12 +0000 |
| commit | a2af9f1993054fa9f9c5ce415f8032558619467c (patch) | |
| tree | c157090320f5caaec414d64bdd3affbcd0b04b80 | |
| parent | cfbd0f43120b3f525e9fc31179c96b4f2d0a0c01 (diff) | |
| download | FreeBSD-src-a2af9f1993054fa9f9c5ce415f8032558619467c.zip FreeBSD-src-a2af9f1993054fa9f9c5ce415f8032558619467c.tar.gz | |
MFp4 //depot/projects/usb@158692
Workaround a EHCI performance problem by issuing a doorbell after queueing a
bulk xfer.
Submitted by: Hans Petter Selasky
| -rw-r--r-- | sys/dev/usb/controller/ehci.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/sys/dev/usb/controller/ehci.c b/sys/dev/usb/controller/ehci.c index 9a5cace..cccd76a 100644 --- a/sys/dev/usb/controller/ehci.c +++ b/sys/dev/usb/controller/ehci.c @@ -2189,12 +2189,21 @@ static void ehci_device_bulk_start(struct usb2_xfer *xfer) { ehci_softc_t *sc = EHCI_BUS2SC(xfer->xroot->bus); + uint32_t temp; /* setup TD's and QH */ ehci_setup_standard_chain(xfer, &sc->sc_async_p_last); /* put transfer on interrupt queue */ ehci_transfer_intr_enqueue(xfer); + + /* XXX Performance quirk: Some Host Controllers have a too low + * interrupt rate. Issue an IAAD to stimulate the Host + * Controller after queueing the BULK transfer. + */ + temp = EOREAD4(sc, EHCI_USBCMD); + if (!(temp & EHCI_CMD_IAAD)) + EOWRITE4(sc, EHCI_USBCMD, temp | EHCI_CMD_IAAD); } struct usb2_pipe_methods ehci_device_bulk_methods = |
