From: Peter Hurley <peter@hurleysoftware.com>
To: "Bollinger, Seth" <Seth.Bollinger@digi.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-serial <linux-serial@vger.kernel.org>
Subject: Re: Possible software flow problem in serial_core
Date: Thu, 20 Mar 2014 20:34:38 -0400 [thread overview]
Message-ID: <532B891E.80705@hurleysoftware.com> (raw)
In-Reply-To: <CF50E0EB.6E95%seth.bollinger@digi.com>
On 03/20/2014 07:34 PM, Bollinger, Seth wrote:
> Do you have a driver that would be a good example of this? From looking
> at serial_core.c:uart_start(), is seems that start_tx() is only called if
> the serial_core ring buffer is not empty. If we don¹t stop the
> transmitter, we slew too many characters.
Yeah, you're right; thanks for catching this.
(I was busy looking at the ll driver and completely missed the bug in
the serial core).
uart_start() should not be conditioning the call to start_tx() on
the ring buffer being empty; ll drivers should already be able to handle
that because CTS flow control change will start_tx regardless of the ring
buffer count.
Will you send a patch?
Regards,
Peter Hurley
next prev parent reply other threads:[~2014-03-21 0:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CF505B08.6E64%seth.bollinger@digi.com>
2014-03-20 23:05 ` Possible software flow problem in serial_core Peter Hurley
2014-03-20 23:34 ` Bollinger, Seth
2014-03-21 0:34 ` Peter Hurley [this message]
2014-03-21 0:48 ` Bollinger, Seth
2014-03-21 1:07 ` Peter Hurley
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