Date: Fri, 27 Oct 2006 06:58:07 GMT From: Warner Losh <imp@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 108551 for review Message-ID: <200610270658.k9R6w7u6051752@repoman.freebsd.org>
next in thread | raw e-mail | index | archive | help
http://perforce.freebsd.org/chv.cgi?CH=108551 Change 108551 by imp@imp_lighthouse on 2006/10/27 06:57:28 read side lower half. Affected files ... .. //depot/projects/arm/src/sys/arm/at91/at91_ssc.c#17 edit Differences ... ==== //depot/projects/arm/src/sys/arm/at91/at91_ssc.c#17 (text+ko) ==== @@ -373,7 +373,42 @@ static int at91_ssc_read(struct cdev *dev, struct uio *uio, int flag) { - return EIO; + struct at91_ssc_softc *sc; + int err, ret, len; + + sc = CDEV2SOFTC(dev); + // must read a multiple of 4 bytes + if ((uio->uio_resid & 0x3) != 0) + return (EINVAL); + err = 0; + ret = 0; + while (uio->uio_resid) { + // If there's no buffered data, but we've already copied + // some data, then go ahead and return what we have now. + if (sc->rd_end == sc->rd_buf && ret != 0) + break; + err = msleep(&sc->rxdone, &sc->sc_mtx, PCATCH | PZERO, + "sscrd", 0); + if (err != 0) + break; + if (sc->rd_end == sc->rd_buf) + continue; + len = MIN(sc->rd_end - sc->rd_buf, uio->uio_resid); + err = uiomove(sc->rd_buf, len, uio); + if (err != 0) + break; + // If we read the whole thing, no datacopy is needed, + // otherwise we move the data down. + ret += len; + if (len == sc->rd_end - sc->rd_buf) + sc->rd_end = sc->rd_buf; + else { + bcopy(sc->rd_buf + len, sc->rd_buf, + sc->rd_end - sc->rd_buf - len); + sc->rd_end -= len; + } + } + return (err); } static int
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200610270658.k9R6w7u6051752>