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Date: Mon, 12 Dec 2005 09:33:37 +0530
From: rashmi ns <nsrashmi@gmail.com>
To: freebsd-hackers@freebsd.org, freebsd-drivers@freebsd.org
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Subject: Help Reqd: "uiomove" transferring zero bytes from user-kernel space
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Hello Team,
                  when i use  "uiomove"  in the character device
interface the no of bytes transfrerred between kernel and userspace is
zero .but the actual data transferred when trraced through
"uio->resid" is correct .can  any one explain why this is happening ?

/*Character Device Interfaces*/
static struct cdevsw  hdlc_cdevsw =3D {

        .d_maj      =3D CDEV_MAJOR,
        .d_open     =3D hdlc_open,
        .d_read     =3D hdlc_read,
        .d_write     =3D hdlc_write,
        .d_ioctl    =3D hdlc_ioctl,
        .d_close    =3D hdlc_close,
        .d_version  =3D D_VERSION,
};
static int hdlc_write(dev_t dev, struct uio *uio, int ioflag)
{
        int     towrite,written;  /*char device inf*/
     written=3Duiomove((void *)write_tx_buffer,towrite,uio);
     uprintf("uio->resid=3D%d",uio->uio_resid);
    uprintf("No of bytes written  =3D%d",written);




}

Thanks and Regards,
Rashmi.N.S