Date: Wed, 4 Mar 2009 22:06:12 GMT From: Hans Petter Selasky <hselasky@FreeBSD.org> To: Perforce Change Reviews <perforce@FreeBSD.org> Subject: PERFORCE change 158692 for review Message-ID: <200903042206.n24M6C74077005@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=158692 Change 158692 by hselasky@hselasky_laptop001 on 2009/03/04 22:05:57 USB controller: EHCI performance quirk. Affected files ... .. //depot/projects/usb/src/sys/dev/usb/controller/ehci.c#2 edit Differences ... ==== //depot/projects/usb/src/sys/dev/usb/controller/ehci.c#2 (text+ko) ==== @@ -2189,12 +2189,23 @@ 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); + + /* Performance quirk: Some Host Controllers have a too low + * interrupt rate. Issue an IAAD to stimulate the Host + * Controller after queueing the BULK transfer. Performance + * increase seen using an off the shelf flash stick: 9 + * Mbytes/second. --hps + */ + 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 =
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