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From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen)
To: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Cc: Breno Leitao <leitao@linux.vnet.ibm.com>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Very strange data loss with jsm driver
Date: Tue, 2 Aug 2011 10:23:53 -0400	[thread overview]
Message-ID: <20110802142353.GP8562@caffeine.csclub.uwaterloo.ca> (raw)
In-Reply-To: <20110802142225.GO8562@caffeine.csclub.uwaterloo.ca>

On Tue, Aug 02, 2011 at 10:22:25AM -0400, Lennart Sorensen wrote:
> On Tue, Aug 02, 2011 at 11:17:52AM -0300, Breno Leitao wrote:
> > Well, I finally tested it over here, and what I found is:
> > 
> > If the line has a \r among the first 16 bytes, then the information
> > is TXed immediately. If there is no \r in the first 16 bytes, then the
> > information seems to be buffered.
> 
> Where in the driver is this happening?
> 
> > So, it seems that that the patch should ask the driver to TX the
> > information when we receive a \r or when the buffer is full. Does it
> > make sense to you ?
> 
> Not sure.  I just wonder why the data is disappearing rather than getting
> buffered somewhere.  Clearly the other serial drivers are doing that
> successfully.
> 
> I don't even know why the driver should care about the contents at all.
> Just send data when it is ready.

Also, do you have any idea how to fix the statistics that 2.6.37 broke?
/proc/tty/driver/jsm used to show TX/RX and such, and that stopped
working.  I managed to fix it on Debian's 2.6.32 kernel which has some
2.6.37 serial stuff backported, but the same fix didn't work on 3.0.0.

-- 
Len Sorensen

  reply	other threads:[~2011-08-02 14:23 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-29 16:04 Very strange data loss with jsm driver Lennart Sorensen
2011-07-29 16:27 ` Alan Cox
2011-07-29 16:53   ` Lennart Sorensen
2011-07-29 18:06     ` Lennart Sorensen
2011-07-29 18:14       ` Alan Cox
2011-07-29 18:13         ` Lennart Sorensen
2011-08-02 14:17           ` Breno Leitao
2011-08-02 14:22             ` Lennart Sorensen
2011-08-02 14:23               ` Lennart Sorensen [this message]
2011-08-02 14:49               ` Breno Leitao
2011-08-02 14:52                 ` Lennart Sorensen

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