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From: Alan Cox <alan@linux.intel.com>
To: Daniel Mack <daniel@caiaq.de>
Cc: linux-kernel@vger.kernel.org, Greg Kroah-Hartman <gregkh@suse.de>,
	Johan Hovold <jhovold@gmail.com>,
	linux-usb@vger.kernel.org
Subject: Re: [PATCH] usb-serial/ftdi_sio: fix DTR/RTS line modes
Date: Thu, 3 Jun 2010 12:32:25 +0100	[thread overview]
Message-ID: <20100603123225.55f544ff@linux.intel.com> (raw)
In-Reply-To: <1275566102-5613-1-git-send-email-daniel@caiaq.de>

On Thu,  3 Jun 2010 13:55:02 +0200
Daniel Mack <daniel@caiaq.de> 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.

If you've got hardware the other end expecting RTS/CTS signals you
really ought to set CRTSCTS. However you patch makes complete sense in
terms of which way it is best to end up.

  reply	other threads:[~2010-06-03 12:19 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-03 11:55 [PATCH] usb-serial/ftdi_sio: fix DTR/RTS line modes Daniel Mack
2010-06-03 11:32 ` Alan Cox [this message]
2010-06-03 12:23   ` Daniel Mack
2010-06-03 11:57 ` Daniel Mack
2010-06-03 14:27   ` Greg KH
2010-06-03 16:21   ` Gene Heskett
2010-06-03 16:26     ` Greg KH
2010-06-03 16:53       ` Gene Heskett
2010-06-06  9:33   ` Ruud Linders
2010-06-06  9:44     ` Daniel Mack

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