From: Jan Kiszka <jan.kiszka@siemens.com>
To: C Smith <csmithquestions@gmail.com>, Xenomai List <xenomai@xenomai.org>
Cc: Steve Freyder <steve@freyder.net>, w1@codecraftsmen.org
Subject: Re: rt_dev_send() stalls periodic task
Date: Thu, 25 Apr 2019 10:23:35 +0200 [thread overview]
Message-ID: <e1a9aa13-c5a4-2ba0-4012-5c668db15e33@siemens.com> (raw)
In-Reply-To: <CA+K1mPHKN42HPMEjQ1aL+P_TjtDt6sUXy95xFRt=y_9qe9y7VQ@mail.gmail.com>
On 25.04.19 09:15, C Smith wrote:
> Hi Jan,
>
> Your patch worked somewhat but not completely. It prevents my app from stalling
> forever, but I caugh the serial transmission itself stalling on the oscilloscope
> for quite a long time. My 72 byte TX packet from the xenomai periodic task gets
> cut in half and there is no transmission for 7msec, then the transmission
> resumes. (I'll send you a screenshot)
What is driver and application state during that phase? Who is waiting on what?
This will be the key to resolve that issue as I'm not yet seeing another mistake
in the driver.
> (Note that I am on xeno 2.6.5 so I merged your 3.x patch above into 16550A.c
> manually.)
>
> I'm currently doing a 12 hour test of your patch plus mine. In my patch I check
> during every RX interrupt to see if I need to call rt_16550_tx_fill() too. I
> know that doesn't work for others but my traffic is full duplex so this test
> will tell us something if it works and maybe we can ultimately get the same
> behavior without my hack.
>
> Also, I made the /.rx_timeout/.tx_timeout /change Jeff found, and it had the
> obvious effect. I can make a patch for xeno 2.6.5 if you want. But I'll point
> out that this fix may break peoples code functionally, so it may be a bad idea
> to fix it on 2.x. Older code was written with a dependence on a truly different
> timeout. It broke my app to fix this because there was suddenly a new unexpected
> timeout. What's your policy on this issue?
The 2.6 repo won't be touched anymore, it's officially dead. If course, you can
share your patch on the list in case there are other remaining users.
Jan
--
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2019-04-25 8:23 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 17:28 rt_dev_send() stalls periodic task C Smith
2019-04-16 8:03 ` Jan Kiszka
2019-04-18 6:42 ` C Smith
2019-04-18 8:36 ` Jan Kiszka
2019-04-21 4:33 ` C Smith
2019-04-21 20:10 ` Steve Freyder
2019-04-22 6:40 ` C Smith
2019-04-22 6:45 ` Jan Kiszka
2019-04-22 19:51 ` Steve Freyder
2019-04-22 20:58 ` Steve Freyder
2019-04-22 22:56 ` C Smith
2019-04-22 23:44 ` Steve Freyder
2019-04-23 12:15 ` Jan Kiszka
2019-04-24 6:53 ` C Smith
2019-04-25 7:15 ` C Smith
2019-04-25 8:23 ` Jan Kiszka [this message]
2019-04-26 0:59 ` C Smith
2019-04-26 16:38 ` Jan Kiszka
2019-04-24 13:05 Jeff Webb
2019-04-24 14:36 ` Jan Kiszka
2019-04-26 0:41 ` Jeff Webb
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