Messages in this thread Patch in this message | | | Date | Thu, 01 Jul 2010 10:35:03 -0700 | From | Greg KH <> | Subject | [patch 117/164] USB: ftdi_sio: fix DTR/RTS line modes |
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2.6.33-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Mack <daniel@caiaq.de>
commit 6a1a82df91fa0eb1cc76069a9efe5714d087eccd upstream.
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@caiaq.de> Cc: Johan Hovold <jhovold@gmail.com> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/usb/serial/ftdi_sio.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -2312,6 +2312,8 @@ static void ftdi_set_termios(struct tty_ "urb failed to set to rts/cts flow control\n"); } + /* raise DTR/RTS */ + set_mctrl(port, TIOCM_DTR | TIOCM_RTS); } else { /* * Xon/Xoff code @@ -2359,6 +2361,8 @@ static void ftdi_set_termios(struct tty_ } } + /* lower DTR/RTS */ + clear_mctrl(port, TIOCM_DTR | TIOCM_RTS); } return; }
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