CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Craig McQueen]

I'm doing a Yocto build of core-image-minimal for imx28evk with 
linux-fslc kernel provider (thus 3.14.19 kernel).

I've found that Busybox 'less' and GNU 'screen' are unresponsive when 
run from the serial debug console (ttyAMA0). E.g. 'less /etc/passwd' 
just hangs and must be stopped with Ctrl-C. 'screen' hangs and must be 
stopped with Ctrl-\.

I traced it to the serial debug console not having CLOCAL bit set. Doing 
'stty clocal' fixes it, so less and screen work normally.

I think CLOCAL should always be set for serial terminals. But I'm new to 
Yocto, and I don't know what/where is needed to change so that CLOCAL 
bit is set for the serial console. Any advice?

Regards,
Craig McQueen

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Nikolay Dimitrov]

Hi Craig,

On 11/11/2014 08:41 AM, Craig McQueen wrote:
> I think CLOCAL should always be set for serial terminals. But I'm new to
> Yocto, and I don't know what/where is needed to change so that CLOCAL
> bit is set for the serial console. Any advice?

Can you build the same kernel version outside Yocto, and test it again 
on your board, co you can compare the behaviors?

Regards,
Nikolay

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Fabio Estevam]

On Tue, Nov 11, 2014 at 4:41 AM, Craig McQueen
<craig.mcqueen@beamcommunications.com> wrote:
> I'm doing a Yocto build of core-image-minimal for imx28evk with linux-fslc
> kernel provider (thus 3.14.19 kernel).
>
> I've found that Busybox 'less' and GNU 'screen' are unresponsive when run
> from the serial debug console (ttyAMA0). E.g. 'less /etc/passwd' just hangs
> and must be stopped with Ctrl-C. 'screen' hangs and must be stopped with
> Ctrl-\.
>
> I traced it to the serial debug console not having CLOCAL bit set. Doing
> 'stty clocal' fixes it, so less and screen work normally.
>
> I think CLOCAL should always be set for serial terminals. But I'm new to
> Yocto, and I don't know what/where is needed to change so that CLOCAL bit is
> set for the serial console. Any advice?

I was able to reproduce this bug on dizzy.

Otavio, any suggestions?

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Cary O'Brien]

Fabio Estevam wrote:
> On Tue, Nov 11, 2014 at 4:41 AM, Craig McQueen
> <craig.mcqueen@beamcommunications.com> wrote:
>> I'm doing a Yocto build of core-image-minimal for imx28evk with linux-fslc
>> kernel provider (thus 3.14.19 kernel).
>>
>> I've found that Busybox 'less' and GNU 'screen' are unresponsive when run
>> from the serial debug console (ttyAMA0). E.g. 'less /etc/passwd' just hangs
>> and must be stopped with Ctrl-C. 'screen' hangs and must be stopped with
>> Ctrl-\.
>>
>> I traced it to the serial debug console not having CLOCAL bit set. Doing
>> 'stty clocal' fixes it, so less and screen work normally.
>>
>> I think CLOCAL should always be set for serial terminals. But I'm new to
>> Yocto, and I don't know what/where is needed to change so that CLOCAL bit is
>> set for the serial console. Any advice?
For whatever it's worth, I have the same situation with Yocto 1.6 and a P1022 board.

Cary O'Brien

> I was able to reproduce this bug on dizzy.
>
> Otavio, any suggestions?

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Otavio Salvador]

On Tue, Nov 11, 2014 at 2:05 PM, Fabio Estevam <festevam@gmail.com> wrote:
> On Tue, Nov 11, 2014 at 4:41 AM, Craig McQueen
> <craig.mcqueen@beamcommunications.com> wrote:
>> I'm doing a Yocto build of core-image-minimal for imx28evk with linux-fslc
>> kernel provider (thus 3.14.19 kernel).
>>
>> I've found that Busybox 'less' and GNU 'screen' are unresponsive when run
>> from the serial debug console (ttyAMA0). E.g. 'less /etc/passwd' just hangs
>> and must be stopped with Ctrl-C. 'screen' hangs and must be stopped with
>> Ctrl-\.
>>
>> I traced it to the serial debug console not having CLOCAL bit set. Doing
>> 'stty clocal' fixes it, so less and screen work normally.
>>
>> I think CLOCAL should always be set for serial terminals. But I'm new to
>> Yocto, and I don't know what/where is needed to change so that CLOCAL bit is
>> set for the serial console. Any advice?
>
> I was able to reproduce this bug on dizzy.
>
> Otavio, any suggestions?

Is it something which needs fixing on the kernel or Busybox getty?

-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Fabio Estevam]

On Tue, Nov 11, 2014 at 3:42 PM, Otavio Salvador
<otavio@ossystems.com.br> wrote:

> Is it something which needs fixing on the kernel or Busybox getty?

It needs to be fixed in Busybox. I tried the same on an LTIB rootfs
and the problem does not happen there.

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Otavio Salvador]

On Tue, Nov 11, 2014 at 3:46 PM, Fabio Estevam <festevam@gmail.com> wrote:
> On Tue, Nov 11, 2014 at 3:42 PM, Otavio Salvador
> <otavio@ossystems.com.br> wrote:
>
>> Is it something which needs fixing on the kernel or Busybox getty?
>
> It needs to be fixed in Busybox. I tried the same on an LTIB rootfs
> and the problem does not happen there.

Please see if you can identify the option (or patch) we need to apply
in Busybox to solve it.

Another possibility is something on your testing LTIB rootfs to be
adding a stty call somewhere.

-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Craig McQueen]

On 12/11/14 04:53, Otavio Salvador wrote:
> On Tue, Nov 11, 2014 at 3:46 PM, Fabio Estevam <festevam@gmail.com> wrote:
>> On Tue, Nov 11, 2014 at 3:42 PM, Otavio Salvador
>> <otavio@ossystems.com.br> wrote:
>>
>>> Is it something which needs fixing on the kernel or Busybox getty?
>> It needs to be fixed in Busybox. I tried the same on an LTIB rootfs
>> and the problem does not happen there.
> Please see if you can identify the option (or patch) we need to apply
> in Busybox to solve it.
>
> Another possibility is something on your testing LTIB rootfs to be
> adding a stty call somewhere.
>

I tried adding the -L option to the getty line in /etc/inittab:

AMA0:12345:respawn:/sbin/getty -L 115200 ttyAMA0

That seemed to work. Not sure yet how to patch that in meta-freescale.

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Otavio Salvador]

[-- Attachment #1: Type: text/plain, Size: 1301 bytes --]

On Tue, Nov 11, 2014 at 9:00 PM, Craig McQueen
<craig.mcqueen@beamcommunications.com> wrote:
> On 12/11/14 04:53, Otavio Salvador wrote:
>>
>> On Tue, Nov 11, 2014 at 3:46 PM, Fabio Estevam <festevam@gmail.com> wrote:
>>>
>>> On Tue, Nov 11, 2014 at 3:42 PM, Otavio Salvador
>>> <otavio@ossystems.com.br> wrote:
>>>
>>>> Is it something which needs fixing on the kernel or Busybox getty?
>>>
>>> It needs to be fixed in Busybox. I tried the same on an LTIB rootfs
>>> and the problem does not happen there.
>>
>> Please see if you can identify the option (or patch) we need to apply
>> in Busybox to solve it.
>>
>> Another possibility is something on your testing LTIB rootfs to be
>> adding a stty call somewhere.
>>
>
> I tried adding the -L option to the getty line in /etc/inittab:
>
> AMA0:12345:respawn:/sbin/getty -L 115200 ttyAMA0
>
> That seemed to work. Not sure yet how to patch that in meta-freescale.

I prepared the patches for OE-Core. I attached both here so you can
confirm it works for you.

If it does, I can add your Reported-by and Tested-by credits :)

-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750

[-- Attachment #2: 0002-systemd-serialgetty-Disable-the-carrier-detect-requi.patch --]
[-- Type: text/x-patch, Size: 1423 bytes --]

From 9d541225d93eeda56e48bcb4caa3b578f3da52a7 Mon Sep 17 00:00:00 2001
From: Otavio Salvador <otavio@ossystems.com.br>
Date: Tue, 11 Nov 2014 21:42:55 -0200
Subject: [PATCH 2/2] systemd-serialgetty: Disable the carrier detect
 requirement for serial consoles
Organization: O.S. Systems Software LTDA.

This aligns the params of getty with the ones used in Debian. From the
getty(8) manpage:

,----[ getty(8) manpage ]
|  -L, --local-line
|
|    Force the line to be a local line with no need for carrier
|    detect. This can be useful when you have a locally attached
|    terminal where the serial line does not set the carrier detect
|    signal.
`----

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
---
 meta/recipes-core/systemd/systemd-serialgetty/serial-getty@.service | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta/recipes-core/systemd/systemd-serialgetty/serial-getty@.service b/meta/recipes-core/systemd/systemd-serialgetty/serial-getty@.service
index 6dd335c..182167b 100644
--- a/meta/recipes-core/systemd/systemd-serialgetty/serial-getty@.service
+++ b/meta/recipes-core/systemd/systemd-serialgetty/serial-getty@.service
@@ -21,7 +21,7 @@ IgnoreOnIsolate=yes
 
 [Service]
 Environment="TERM=xterm"
-ExecStart=-/sbin/agetty -8 --keep-baud %I @BAUDRATE@ $TERM
+ExecStart=-/sbin/agetty -8 -L --keep-baud %I @BAUDRATE@ $TERM
 Type=idle
 Restart=always
 RestartSec=0
-- 
2.1.1


[-- Attachment #3: 0001-sysvinit-inittab-Disable-the-carrier-detect-requirem.patch --]
[-- Type: text/x-patch, Size: 1463 bytes --]

From 8fdf52fe1103ad4d49d5a7c0bbae53013710fdf0 Mon Sep 17 00:00:00 2001
From: Otavio Salvador <otavio@ossystems.com.br>
Date: Tue, 11 Nov 2014 21:33:22 -0200
Subject: [PATCH 1/2] sysvinit-inittab: Disable the carrier detect requirement
 for serial consoles
Organization: O.S. Systems Software LTDA.

This aligns the params of getty with the ones used in Debian. From the
getty(8) manpage:

,----[ getty(8) manpage ]
|  -L, --local-line
|
|    Force the line to be a local line with no need for carrier
| 	 detect. This can be useful when you have a locally attached
| 	 terminal where the serial line does not set the carrier detect
| 	 signal.
`----

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
---
 meta/recipes-core/sysvinit/sysvinit-inittab_2.88dsf.bb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta/recipes-core/sysvinit/sysvinit-inittab_2.88dsf.bb b/meta/recipes-core/sysvinit/sysvinit-inittab_2.88dsf.bb
index c3244b4..657ef02 100644
--- a/meta/recipes-core/sysvinit/sysvinit-inittab_2.88dsf.bb
+++ b/meta/recipes-core/sysvinit/sysvinit-inittab_2.88dsf.bb
@@ -23,7 +23,7 @@ do_install() {
     do
 	j=`echo ${i} | sed s/\;/\ /g`
 	label=`echo ${i} | sed -e 's/^.*;tty//' -e 's/;.*//'`
-	echo "$label:12345:respawn:${base_sbindir}/getty ${j}" >> ${D}${sysconfdir}/inittab
+	echo "$label:12345:respawn:${base_sbindir}/getty -L ${j}" >> ${D}${sysconfdir}/inittab
     done
 
     if [ "${USE_VT}" = "1" ]; then
-- 
2.1.1

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Craig McQueen]

On 12/11/14 10:47, Otavio Salvador wrote:
> On Tue, Nov 11, 2014 at 9:00 PM, Craig McQueen
> <craig.mcqueen@beamcommunications.com> wrote:
>> On 12/11/14 04:53, Otavio Salvador wrote:
>>> On Tue, Nov 11, 2014 at 3:46 PM, Fabio Estevam <festevam@gmail.com> wrote:
>>>> On Tue, Nov 11, 2014 at 3:42 PM, Otavio Salvador
>>>> <otavio@ossystems.com.br> wrote:
>>>>
>>>>> Is it something which needs fixing on the kernel or Busybox getty?
>>>> It needs to be fixed in Busybox. I tried the same on an LTIB rootfs
>>>> and the problem does not happen there.
>>> Please see if you can identify the option (or patch) we need to apply
>>> in Busybox to solve it.
>>>
>>> Another possibility is something on your testing LTIB rootfs to be
>>> adding a stty call somewhere.
>>>
>> I tried adding the -L option to the getty line in /etc/inittab:
>>
>> AMA0:12345:respawn:/sbin/getty -L 115200 ttyAMA0
>>
>> That seemed to work. Not sure yet how to patch that in meta-freescale.
> I prepared the patches for OE-Core. I attached both here so you can
> confirm it works for you.
>
> If it does, I can add your Reported-by and Tested-by credits :)
>

Great! I have tested the inittab patch, and it works. Thanks. I haven't 
tested the systemd patch.

-- 
Craig McQueen

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Colin Moloney]

Craig McQueen <craig.mcqueen@...> writes:

> 
> I'm doing a Yocto build of core-image-minimal for imx28evk with 
> linux-fslc kernel provider (thus 3.14.19 kernel).
> 
... snip
> 
> Regards,
> Craig McQueen

Hi Craig,
   I want to do exactly the same thing but as a newcomer to Yocto I'm lost
in the mass of configuration.
   In my extract of  "repo init -u
https://github.com/Freescale/fsl-community-bsp-platform -b daisy" I can only
find the imx28evk under
"sources/meta-fsl-arm/recipes-kernel/linux/linux-imx-2.6.35.3" and only the
"mxs" under other ".../linux/linux-..." directories.
   The 'machine/conf' file sources/meta-fsl-arm/conf/machine/imx28evk.conf
refers to conf/machine/include/mxs-base.inc which has:
    PREFERRED_PROVIDER_virtual/kernel_mx23 ?= "linux-fslc"
but I get linux-imx-2.6.35.3 when I build.

   Do you know where I can find an explanation of how to change the imx28evk
to a more recent kernel (3.14 or 3.10.17) ?

Regards

Colin Moloney

Re: CLOCAL bit for console ttyAMA0 on imx28evk with 3.14 kernel

[Otavio Salvador]

Hello Colin,

On Fri, Jan 2, 2015 at 5:10 AM, Colin Moloney <cmoloney@mtdata.com.au> wrote:
> Craig McQueen <craig.mcqueen@...> writes:
>> I'm doing a Yocto build of core-image-minimal for imx28evk with
>> linux-fslc kernel provider (thus 3.14.19 kernel).
>>
> ... snip
>>
>> Regards,
>> Craig McQueen
>
> Hi Craig,
>    I want to do exactly the same thing but as a newcomer to Yocto I'm lost
> in the mass of configuration.
>    In my extract of  "repo init -u
> https://github.com/Freescale/fsl-community-bsp-platform -b daisy" I can only
> find the imx28evk under
> "sources/meta-fsl-arm/recipes-kernel/linux/linux-imx-2.6.35.3" and only the
> "mxs" under other ".../linux/linux-..." directories.
>    The 'machine/conf' file sources/meta-fsl-arm/conf/machine/imx28evk.conf
> refers to conf/machine/include/mxs-base.inc which has:
>     PREFERRED_PROVIDER_virtual/kernel_mx23 ?= "linux-fslc"
> but I get linux-imx-2.6.35.3 when I build.
>
>    Do you know where I can find an explanation of how to change the imx28evk
> to a more recent kernel (3.14 or 3.10.17) ?

You can set:

PREFERRED_PROVIDER_virtual/kernel = "linux-fslc"

in your local.conf. It should do the trick.

-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750