Re: [PATCH] usb-serial/ftdi_sio: fix DTR/RTS line modes

From: Greg KH
Date: Thu Jun 03 2010 - 10:29:45 EST


On Thu, Jun 03, 2010 at 01:57:27PM +0200, Daniel Mack wrote:
> On Thu, Jun 03, 2010 at 01:55:02PM +0200, Daniel Mack wrote:
> > Call set_mctrl() and clear_mctrl() according to the flow control mode
> > selected. This makes serial communication for FT232 connected devices
> > work when CRTSCTS is not set.
> >
> > This fixes a regression introduced by 4175f3e31 ("tty_port: If we are
> > opened non blocking we still need to raise the carrier"). This patch
> > calls the low-level driver's dtr_rts() function which consequently sets
> > TIOCM_DTR | TIOCM_RTS. A later call to set_termios() without CRTSCTS in
> > cflags, however, does not reset these bits, and so data is not actually
> > sent out on the serial wire.
> >
> > Signed-off-by: Daniel Mack <daniel@xxxxxxxx>
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
> > Cc: Johan Hovold <jhovold@xxxxxxxxx>
> > Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
> > Cc: linux-usb@xxxxxxxxxxxxxxx
>
> Oops. I forgot to Cc: stable@xxxxxxxxxxx
> This is in fact broken since 2.6.31-something.

Thanks for letting me know, I'll add that marking to the patch when I
queue it up.

thanks,

greg k-h
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