Pete, My apology, reading Greg's post I realized that 2.6.35 (distributed with Fedora 14) is indeed outdated. I just checked out 2.6.37-rc7 tree and saw references to get_icount function. I will definetely address your concern, Thank you again, Vadim. --- On Sun, 12/26/10, Tsozik <tsozik@xxxxxxxxx> wrote: > From: Tsozik <tsozik@xxxxxxxxx> > Subject: Re: [PATCH 1/1] mct_u232: IOCTL implementation > To: "Pete Zaitcev" <zaitcev@xxxxxxxxxx> > Cc: "Greg Kroah-Hartman" <gregkh@xxxxxxx>, linux-usb@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx > Date: Sunday, December 26, 2010, 2:41 PM > Pete, > > Many thanks for your comment/concern. I borrowed an > TIOCGICOUNT implementation from usb/serial/io_ti.c: > > case TIOCGICOUNT: > > dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d", __func__, > > port->number, > edge_port->icount.rx, edge_port->icount.tx); > if > (copy_to_user((void __user *)arg, > &edge_port->icount, > > > sizeof(edge_port->icount))) > > return -EFAULT; > > return 0; > } > > There are 2 similar TIOCGICOUNT implementations listed in > > ark3116.c > io_edgeport.c > io_ti.c > mos7720.c > mos7840.c > ti_usb_3410_5052.c > > files under usb/serial/ directory. One based on io_ti.c and > another based on io_edgeport.c. I borrowed one from io_ti.c, > since it looked more effecient to me. I searched for any > mention of get_icount function under linux-2.6.35 and didn't > find any file which declared or called this function: > > [vtsozik@SR71 linux-2.6.35]$ find . -type f -name '*.[c,h]' > | xargs grep get_icount > [vtsozik@SR71 linux-2.6.35]$ > > I'm wondering if you could give me a bit more information > on this. Otherwise I would really prefer to proceed with > something that already exists and tested. If by some reason > you believe that alternative implementation from > io_edgeport.c (please see code snippet below) should be used > please let me know. Again I didn't see any reason for extra > copy. > > case TIOCGICOUNT: > > cnow = edge_port->icount; > > memset(&icount, 0, sizeof(icount)); > > icount.cts = cnow.cts; > > icount.dsr = cnow.dsr; > > icount.rng = cnow.rng; > > icount.dcd = cnow.dcd; > > icount.rx = cnow.rx; > > icount.tx = cnow.tx; > > icount.frame = cnow.frame; > > icount.overrun = cnow.overrun; > > icount.parity = cnow.parity; > > icount.brk = cnow.brk; > > icount.buf_overrun = cnow.buf_overrun; > > > dbg("%s (%d) TIOCGICOUNT RX=%d, TX=%d", > > > __func__, port->number, icount.rx, icount.tx); > if > (copy_to_user((void __user *)arg, &icount, > sizeof(icount))) > > return -EFAULT; > > return 0; > } > > Thank you in advance, > Vadim. > > --- On Sun, 12/26/10, Pete Zaitcev <zaitcev@xxxxxxxxxx> > wrote: > > > From: Pete Zaitcev <zaitcev@xxxxxxxxxx> > > Subject: Re: [PATCH 1/1] mct_u232: IOCTL > implementation > > To: "Tsozik" <tsozik@xxxxxxxxx> > > Cc: "Greg Kroah-Hartman" <gregkh@xxxxxxx>, > linux-usb@xxxxxxxxxxxxxxx, > linux-kernel@xxxxxxxxxxxxxxx > > Date: Sunday, December 26, 2010, 12:49 PM > > On Sat, 25 Dec 2010 21:39:39 -0800 > > (PST) > > Tsozik <tsozik@xxxxxxxxx> > > wrote: > > > > > +++ mct_u232.c 2010-12-25 21:44:57.714640343 > > -0500 > > > +static int mct_u232_ioctl(struct tty_struct > > *tty, struct file *file, > > > + > > unsigned int cmd, > > unsigned long arg) > > > +{ > > > + case TIOCGICOUNT: > > > + > > dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d", > __func__, > > > + > > port->number, > > mct_u232_port->icount.rx, > mct_u232_port->icount.tx); > > > + > > if (copy_to_user((void __user *)arg, > > &mct_u232_port->icount, > > > + > > sizeof(mct_u232_port->icount))) > > > + > > return -EFAULT; > > > > This looks suspicious. Didn't we relocate the > machinery for > > TIOCGICOUNT > > into a generic place? Please examine how > ->get_icount > > works before > > hand-rolling the ioctl. > > > > -- Pete > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html