From a2af9f1993054fa9f9c5ce415f8032558619467c Mon Sep 17 00:00:00 2001 From: thompsa Date: Fri, 6 Mar 2009 17:13:12 +0000 Subject: MFp4 //depot/projects/usb@158692 Workaround a EHCI performance problem by issuing a doorbell after queueing a bulk xfer. Submitted by: Hans Petter Selasky --- sys/dev/usb/controller/ehci.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'sys/dev/usb/controller') 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 = -- cgit v1.1