[C8000] serial console drops input

[C8000] serial console drops input

[Jeroen Roovers]

In recent kernels, with the new serial console code for the C8000,
performance is terrible. Typing quickly results in characters getting
dropped (I have no idea where I lose them), pasting results in 9 out of
10 characters being dropped, and I don't see anything on the client
side that could cause this, and I never had this problem with the old
ttyB0 code. While entering a password, some characters never turn up on
the other side and some get echoed back to the client.

Is anyone else seeing this?


Regards,
     jer

Re: [C8000] serial console drops input

[Rolf Eike Beer]

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Am Samstag, 25. Januar 2014, 05:41:44 schrieben Sie:
> In recent kernels, with the new serial console code for the C8000,
> performance is terrible. Typing quickly results in characters getting
> dropped (I have no idea where I lose them), pasting results in 9 out of
> 10 characters being dropped, and I don't see anything on the client
> side that could cause this, and I never had this problem with the old
> ttyB0 code. While entering a password, some characters never turn up on
> the other side and some get echoed back to the client.
> 
> Is anyone else seeing this?

What I see is that the C3600 now finally sees the kernel/console output of the 
C8000, I also see the login prompt, but typing anything on the C3600 doesn't 
seem to make it to the C8k. So things have improved, I now can actually see 
what's going on on the C8k, but I can't interact with it.

Eike

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Re: [C8000] serial console drops input

[John David Anglin]

On 25-Jan-14, at 3:20 AM, Rolf Eike Beer wrote:

> Am Samstag, 25. Januar 2014, 05:41:44 schrieben Sie:
>> In recent kernels, with the new serial console code for the C8000,
>> performance is terrible. Typing quickly results in characters getting
>> dropped (I have no idea where I lose them), pasting results in 9  
>> out of
>> 10 characters being dropped, and I don't see anything on the client
>> side that could cause this, and I never had this problem with the old
>> ttyB0 code. While entering a password, some characters never turn  
>> up on
>> the other side and some get echoed back to the client.
>>
>> Is anyone else seeing this?
>
> What I see is that the C3600 now finally sees the kernel/console  
> output of the
> C8000, I also see the login prompt, but typing anything on the C3600  
> doesn't
> seem to make it to the C8k. So things have improved, I now can  
> actually see

Is XON/XOFF enabled in your terminal program?  See c8000 Technical  
Reference
Guide for setup requirements

I'm using standard PC null modem cable from c3750 to c8000 and minicom  
2.7.  It works
fine but it's fairly slow.

Dave
--
John David Anglin	dave.anglin@bell.net

Re: [C8000] serial console drops input

[Rolf Eike Beer]

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Am Samstag 25 Januar 2014, 11:29:22 schrieb John David Anglin:
> On 25-Jan-14, at 3:20 AM, Rolf Eike Beer wrote:
> > Am Samstag, 25. Januar 2014, 05:41:44 schrieben Sie:
> >> In recent kernels, with the new serial console code for the C8000,
> >> performance is terrible. Typing quickly results in characters getting
> >> dropped (I have no idea where I lose them), pasting results in 9
> >> out of
> >> 10 characters being dropped, and I don't see anything on the client
> >> side that could cause this, and I never had this problem with the old
> >> ttyB0 code. While entering a password, some characters never turn
> >> up on
> >> the other side and some get echoed back to the client.
> >> 
> >> Is anyone else seeing this?
> > 
> > What I see is that the C3600 now finally sees the kernel/console
> > output of the
> > C8000, I also see the login prompt, but typing anything on the C3600
> > doesn't
> > seem to make it to the C8k. So things have improved, I now can
> > actually see
> 
> Is XON/XOFF enabled in your terminal program?  See c8000 Technical
> Reference
> Guide for setup requirements
> 
> I'm using standard PC null modem cable from c3750 to c8000 and minicom
> 2.7.  It works
> fine but it's fairly slow.

Both on and off doesn't make a difference.

One other thing: the serial line from the C8000 to my Sun Fire V240 works 
flawlessly.

Eike

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Re: [C8000] serial console drops input

[John David Anglin]

On 25-Jan-14, at 11:34 AM, Rolf Eike Beer wrote:

> Am Samstag 25 Januar 2014, 11:29:22 schrieb John David Anglin:
>> On 25-Jan-14, at 3:20 AM, Rolf Eike Beer wrote:
>>> Am Samstag, 25. Januar 2014, 05:41:44 schrieben Sie:
>>>> In recent kernels, with the new serial console code for the C8000,
>>>> performance is terrible. Typing quickly results in characters  
>>>> getting
>>>> dropped (I have no idea where I lose them), pasting results in 9
>>>> out of
>>>> 10 characters being dropped, and I don't see anything on the client
>>>> side that could cause this, and I never had this problem with the  
>>>> old
>>>> ttyB0 code. While entering a password, some characters never turn
>>>> up on
>>>> the other side and some get echoed back to the client.
>>>>
>>>> Is anyone else seeing this?
>>>
>>> What I see is that the C3600 now finally sees the kernel/console
>>> output of the
>>> C8000, I also see the login prompt, but typing anything on the C3600
>>> doesn't
>>> seem to make it to the C8k. So things have improved, I now can
>>> actually see
>>
>> Is XON/XOFF enabled in your terminal program?  See c8000 Technical
>> Reference
>> Guide for setup requirements
>>
>> I'm using standard PC null modem cable from c3750 to c8000 and  
>> minicom
>> 2.7.  It works
>> fine but it's fairly slow.
>
> Both on and off doesn't make a difference.
>
> One other thing: the serial line from the C8000 to my Sun Fire V240  
> works
> flawlessly.


Same cable?  Does boot output look ok or are characters dropped?
Which kernels specifically (c8000 can c3600)?

Dave
--
John David Anglin	dave.anglin@bell.net

Re: [C8000] serial console drops input

[Rolf Eike Beer]

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> > One other thing: the serial line from the C8000 to my Sun Fire V240
> > works
> > flawlessly.
> 
> Same cable?  Does boot output look ok or are characters dropped?
> Which kernels specifically (c8000 can c3600)?

c8000: 3.12.5 minus the mmap patch (the same for 3.12.8)
c3600: 3.12.5

Boot output looks fine. Cables are normal nullmodem. I can interact using 
minicom with the firmware, i.e. typing "BO PRI<return>N<return>" or things 
like that work fine.

Eike

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Re: [C8000] serial console drops input

[Jeroen Roovers]

On Sat, 25 Jan 2014 18:03:17 +0100
Rolf Eike Beer <eike-kernel@sf-tec.de> wrote:

> Boot output looks fine. Cables are normal nullmodem. I can interact
> using minicom with the firmware, i.e. typing "BO
> PRI<return>N<return>" or things like that work fine.

Yes, in the PDC everything still seems fine.

But as early as in the IPL I can't paste a string without
characters dropping (which is how I first noticed the issue, since
that's where I normally do this to select a kernel to boot). So did the
IPL change as well, then?



     jer

Re: [C8000] serial console drops input

[Dave Land]

On 1/25/14 10:13 AM, Jeroen Roovers wrote:
> On Sat, 25 Jan 2014 18:03:17 +0100
> Rolf Eike Beer <eike-kernel@sf-tec.de> wrote:
>
>> Boot output looks fine. Cables are normal nullmodem. I can interact
>> using minicom with the firmware, i.e. typing "BO
>> PRI<return>N<return>" or things like that work fine.
>
> Yes, in the PDC everything still seems fine.
>
> But as early as in the IPL I can't paste a string without
> characters dropping (which is how I first noticed the issue, since
> that's where I normally do this to select a kernel to boot). So did the
> IPL change as well, then?
>
>
>
>       jer
> --
> To unsubscribe from this list: send the line "unsubscribe linux-parisc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
(I probably should have hit reply-all on this before...)

Just as an FYI, I had some of the same behavior when I first set my 
J6750 up with a serial line (null modem cable to a secondary machine)
Usually had to type the p/w 2 or 3 times to get it to 'take' in minicom. 
One thing I *did* notice was the *length* of the null modem cable and 
the proximity of the 2 machines seemed to make a difference (bad cable 
shielding maybe?) Just my 2 cents. (Running Kernel Ver. 3.12.6-2 at the 
moment)

...and like Dave A. mentioned, Xon/Xoff makes a difference too.

Dave L.

P.S. Now that it's up and running, and I usually log in with PUTTY or 
the STIcon graphics console, it's not a problem anymore. :-)
-- 
Dave Land
Land Computer Service  xmechanic@landcomp.net
ICQ: 676030523

Re: [C8000] serial console drops input

[Dave Land]

On 1/25/14 12:54 PM, Dave Land wrote:
> On 1/25/14 10:13 AM, Jeroen Roovers wrote:
>> On Sat, 25 Jan 2014 18:03:17 +0100
>> Rolf Eike Beer <eike-kernel@sf-tec.de> wrote:
>>
>>> Boot output looks fine. Cables are normal nullmodem. I can interact
>>> using minicom with the firmware, i.e. typing "BO
>>> PRI<return>N<return>" or things like that work fine.
>>
>> Yes, in the PDC everything still seems fine.
>>
>> But as early as in the IPL I can't paste a string without
>> characters dropping (which is how I first noticed the issue, since
>> that's where I normally do this to select a kernel to boot). So did the
>> IPL change as well, then?
>>
>>
>>
>>       jer
>> --
>> To unsubscribe from this list: send the line "unsubscribe
>> linux-parisc" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
> (I probably should have hit reply-all on this before...)
>
> Just as an FYI, I had some of the same behavior when I first set my
> J6750 up with a serial line (null modem cable to a secondary machine)
> Usually had to type the p/w 2 or 3 times to get it to 'take' in minicom.
> One thing I *did* notice was the *length* of the null modem cable and
> the proximity of the 2 machines seemed to make a difference (bad cable
> shielding maybe?) Just my 2 cents. (Running Kernel Ver. 3.12.6-2 at the
> moment)
>
> ...and like Dave A. mentioned, Xon/Xoff makes a difference too.
>
> Dave L.
>
> P.S. Now that it's up and running, and I usually log in with PUTTY or
> the STIcon graphics console, it's not a problem anymore. :-)

One other thing... If you're using the serial line, make sure you don't 
have a monitor or keyboard & mouse hooked to the target machine (I know 
the C8000's are graphics capable and most likely have usb ports for 
keyboard and mouse, the same as my J6750.) This seems to confuse the 
machine in the early setup stages, at least it did make a difference on 
mine.

Dave L.

-- 
Dave Land
Land Computer Service  xmechanic@landcomp.net
ICQ: 676030523

Re: [C8000] serial console drops input

[John David Anglin]

On 25-Jan-14, at 12:13 PM, Jeroen Roovers wrote:

> On Sat, 25 Jan 2014 18:03:17 +0100
> Rolf Eike Beer <eike-kernel@sf-tec.de> wrote:
>
>> Boot output looks fine. Cables are normal nullmodem. I can interact
>> using minicom with the firmware, i.e. typing "BO
>> PRI<return>N<return>" or things like that work fine.
>
> Yes, in the PDC everything still seems fine.
>
> But as early as in the IPL I can't paste a string without
> characters dropping (which is how I first noticed the issue, since
> that's where I normally do this to select a kernel to boot). So did  
> the
> IPL change as well, then?


Helge has made some changes to palo but I believe that we are on the  
PDC boot
console (ttyB0) until switch over here:

Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
17: ttyS0 at MMIO 0xfffffff0f05e0800 (irq = 75, base_baud = 115200) is  
a 16550A
console [ttyS0] enabled, bootconsole disabled
console [ttyS0] enabled, bootconsole disabled
18: ttyS1 at MMIO 0xfffffff0f05e2800 (irq = 76, base_baud = 115200) is  
a 16550A

The PDC code is in firmware.

How long is your cable?    There's no shield connection on DB9  
connector.  You just
need to cross transmit and receive data.  Signal ground is straight  
through.

Dave L is correct about USB keyboard and mouse confusing serial  
console support.

Dave
--
John David Anglin	dave.anglin@bell.net

Re: [C8000] serial console drops input

[Jeroen Roovers]

On Sat, 25 Jan 2014 15:13:47 -0500
John David Anglin <dave.anglin@bell.net> wrote:

> Helge has made some changes to palo but I believe that we are on the  
> PDC boot
> console (ttyB0) until switch over here:

This.

> How long is your cable?    There's no shield connection on DB9  
> connector.  You just
> need to cross transmit and receive data.  Signal ground is straight  
> through.
> 
> Dave L is correct about USB keyboard and mouse confusing serial  
> console support.

Yes, but _all_ of that is entirely immaterial as the same hardware
worked fine for more than one and a half years, _until_ the changes to
palo/PDC console support were introduced.

I could easily revert the IPL to the former working version (1.18) and
see if that fixes the issue during boot. I'll report back with some
results.

Re: [C8000] serial console drops input

[Dave Land]

On 1/25/14 5:02 PM, Jeroen Roovers wrote:
> On Sat, 25 Jan 2014 15:13:47 -0500
> John David Anglin <dave.anglin@bell.net> wrote:
>
>> Helge has made some changes to palo but I believe that we are on the
>> PDC boot
>> console (ttyB0) until switch over here:
>
> This.
>
>> How long is your cable?    There's no shield connection on DB9
>> connector.  You just
>> need to cross transmit and receive data.  Signal ground is straight
>> through.
>>
>> Dave L is correct about USB keyboard and mouse confusing serial
>> console support.
>
> Yes, but _all_ of that is entirely immaterial as the same hardware
> worked fine for more than one and a half years, _until_ the changes to
> palo/PDC console support were introduced.

Ahh, I missed that part... :-P I think I set mine up after this was 
introduced.

Dave L.

>
> I could easily revert the IPL to the former working version (1.18) and
> see if that fixes the issue during boot. I'll report back with some
> results.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-parisc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>


-- 
Dave Land
Land Computer Service  xmechanic@landcomp.net
ICQ: 676030523

Re: [C8000] serial console drops input

[Helge Deller]

On 01/26/2014 01:02 AM, Jeroen Roovers wrote:
> On Sat, 25 Jan 2014 15:13:47 -0500
> John David Anglin <dave.anglin@bell.net> wrote:
> 
>> Helge has made some changes to palo but I believe that we are on the  
>> PDC boot
>> console (ttyB0) until switch over here:
> 
> This.
> 
>> How long is your cable?    There's no shield connection on DB9  
>> connector.  You just
>> need to cross transmit and receive data.  Signal ground is straight  
>> through.
>>
>> Dave L is correct about USB keyboard and mouse confusing serial  
>> console support.
> 
> Yes, but _all_ of that is entirely immaterial as the same hardware
> worked fine for more than one and a half years, _until_ the changes to
> palo/PDC console support were introduced.
> 
> I could easily revert the IPL to the former working version (1.18) and
> see if that fixes the issue during boot. I'll report back with some
> results.

I'm pretty sure that I didn't changed anything in palo which is PDC-console
related and which would explain why you have such problems.
If there is a problem, then it might be because of kernel and/or cable.

Helge

Re: [C8000] serial console drops input

[Jeroen Roovers]

On Sun, 26 Jan 2014 16:07:18 +0100
Helge Deller <deller@gmx.de> wrote:

> I'm pretty sure that I didn't changed anything in palo which is
> PDC-console related and which would explain why you have such
> problems. If there is a problem, then it might be because of kernel
> and/or cable.

Yes, that seems to be the case. I initially assumed something might
actually reconfigure the serial port in the IPL, but I can't find any
evidence in support.

I think I am seeing two problems:

1) Pasting strings doesn't work on either the PDC console or the
   IPL/Linux console.

2) Whereas typing on the PDC console works fine, even at some speed,
   the same is not true for the IPL/Linux console, which lose many
   characters along the way, and act as if the connection is
   temporarily lost. Switching the client side terminal program
   (I tested with minicom, picocom, screen) makes no difference.

Do serial cables deteriorate over time? :-)


Regards,
     jer

Re: [C8000] serial console drops input

[Dave Land]

On 1/26/14 1:22 PM, Jeroen Roovers wrote:
> On Sun, 26 Jan 2014 16:07:18 +0100
> Helge Deller <deller@gmx.de> wrote:
>
>> I'm pretty sure that I didn't changed anything in palo which is
>> PDC-console related and which would explain why you have such
>> problems. If there is a problem, then it might be because of kernel
>> and/or cable.
>
> Yes, that seems to be the case. I initially assumed something might
> actually reconfigure the serial port in the IPL, but I can't find any
> evidence in support.
>
> I think I am seeing two problems:
>
> 1) Pasting strings doesn't work on either the PDC console or the
>     IPL/Linux console.
>
> 2) Whereas typing on the PDC console works fine, even at some speed,
>     the same is not true for the IPL/Linux console, which lose many
>     characters along the way, and act as if the connection is
>     temporarily lost. Switching the client side terminal program
>     (I tested with minicom, picocom, screen) makes no difference.
>
> Do serial cables deteriorate over time? :-)
>
>
> Regards,
>       jer
> --

Jeroen,

It is a possibility that the serial cable may be a problem, or there may 
actually be a hardware issue with the machine itself.(Most of these 
machines are pretty old by computer world standards) :-) Sometimes just 
giving them a good cleaning with compressed air, and re-seating the RAM 
modules will make a difference. Just a thought... ;-)

Dave L.

P.S. I live in an area where dust is a major problem, and I have to blow 
the dust and crap out of mine about every 3 months or so. If I don't; 
when it *does* rain around here and the humidity goes up, I get all 
kinds of weird errors on some of my machines (the dust becomes 
electrically conductive). I experience this a lot with my customers 
machines too.

-- 
Dave Land
Land Computer Service  xmechanic@landcomp.net
ICQ: 676030523

Re: [C8000] serial console drops input

[John David Anglin]

On 26-Jan-14, at 3:22 PM, Jeroen Roovers wrote:

> Do serial cables deteriorate over time? :-)

Not much although the soldered/crimped connections could break.  More  
of an issue is the
drivers.  Many boards use +3.3V devices such as the MAX3232.  These  
don't put out as much voltage
on the cable as standard RS232 drivers.  So, they can't drive as much  
cable as a fully standard device.
Secondly, the driver chips are sensitive to ESD damage (particularly  
receiver).  So, they could
get zapped, particularly if devices are connected while running when a  
connection is made.
Currents can also flow through the cable when the grounds for the two  
pieces of equipment
is the same.  There is no isolation in RS232 so it is sensitive to ESD  
problem.  There is an 'E'
version of most RS232 driver devices which has improved (+15KV human  
body) ESD protection.

I've seen quite a few devices die in the lab.  The charge pump on  
these devices is also sometimes
a problem.

Without a scope, it's hard to tell when the signals are bad.  Best  
that can be done is to test both
units with third device using same/different cables, etc.

Dave
--
John David Anglin	dave.anglin@bell.net

Re: [C8000] serial console drops input

[John David Anglin]

On 26-Jan-14, at 4:01 PM, John David Anglin wrote:

> Currents can also flow through the cable when the grounds for the  
> two pieces of equipment
> is the same.

"not the same".

--
John David Anglin	dave.anglin@bell.net