[U-Boot] imx27lite stability problems.

[U-Boot] imx27lite stability problems.

[javier Martin]

I have tried u-boot for the imx27lite board from LogicPD which is
currently in u-boot-arm repository and I have experienced some
stability problems:
- Sometimes the system gets stuck in serial_getc() from serial_mxc.c
driver when printing information (ex. mii read ).
- Pings do not work properly, the system gets stuck in fec_send()
function waiting always for a frame to be sent (which actually does
not happen).
- Sometimes the system gets stuck when saving the environment to flash
'saveenv', but other times it does it well.

I would like to help to solve this problems, but I don't know exactly
where to begin from. I have been reviewing clock settings. Could this
be happening because this board is using 32KHz xtal as reference
instead of 26MHz one?

Have you experienced these problems also?

Thank you.

-- 
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com

[U-Boot] imx27lite stability problems.

[Wolfgang Denk]

Dear javier Martin,

In message <eedb5540909170031k7b9076eeo8d4f60c799f1a27c@mail.gmail.com> you wrote:
> I have tried u-boot for the imx27lite board from LogicPD which is
> currently in u-boot-arm repository and I have experienced some
> stability problems:
> - Sometimes the system gets stuck in serial_getc() from serial_mxc.c
> driver when printing information (ex. mii read ).
> - Pings do not work properly, the system gets stuck in fec_send()
> function waiting always for a frame to be sent (which actually does
> not happen).
> - Sometimes the system gets stuck when saving the environment to flash
> 'saveenv', but other times it does it well.

We don't see any such issues on the board we have here in the lab.

> I would like to help to solve this problems, but I don't know exactly
> where to begin from. I have been reviewing clock settings. Could this
> be happening because this board is using 32KHz xtal as reference
> instead of 26MHz one?

Yes, of course this could be a problem. Is this an original LogicPD
board?  Did you adapt the code for the different clock speed? What
exactly did you change?

> Have you experienced these problems also?

No, we didn't.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Monday is an awful way to spend one seventh of your life.

[U-Boot] imx27lite stability problems.

[javier Martin]

2009/9/17 Wolfgang Denk <wd@denx.de>:
> Dear javier Martin,
>
> In message <eedb5540909170031k7b9076eeo8d4f60c799f1a27c@mail.gmail.com> you wrote:
>> I have tried u-boot for the imx27lite board from LogicPD which is
>> currently in u-boot-arm repository and I have experienced some
>> stability problems:
>> - Sometimes the system gets stuck in serial_getc() from serial_mxc.c
>> driver when printing information (ex. mii read ).
>> - Pings do not work properly, the system gets stuck in fec_send()
>> function waiting always for a frame to be sent (which actually does
>> not happen).
>> - Sometimes the system gets stuck when saving the environment to flash
>> 'saveenv', but other times it does it well.
>
> We don't see any such issues on the board we have here in the lab.
>
>> I would like to help to solve this problems, but I don't know exactly
>> where to begin from. I have been reviewing clock settings. Could this
>> be happening because this board is using 32KHz xtal as reference
>> instead of 26MHz one?
>
> Yes, of course this could be a problem. Is this an original LogicPD
> board? ?Did you adapt the code for the different clock speed? What
> exactly did you change?

Sorry, I am not trying it on an original LogicPD board. Our board is
based in i.mx27 ipcam. We have a different phy which is in 0x0 address
instead of 0x1F and we have also a different NOR flash model. We have
also the external 32KHz xtal at 32.768 KHz.

- The init code for our sdram is different as we have different model
and memory configuration, however I made a memory test and all seems
fine.
- I adapted NOR flash configuration and PHY_ADDRESS only, and
experienced the previous problems. I could expect issues with NOR
flash but I don't know why I could have any issue with ethernet.


>
>> Have you experienced these problems also?
>
> No, we didn't.
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH, ? ? MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> Monday is an awful way to spend one seventh of your life.
>



-- 
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com

[U-Boot] imx27lite stability problems.

[javier Martin]

I've found some problems because the cache is enabled, I don't see any
place where you disable it.

Are you sure you have this controlled properly?

-- 
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com

[U-Boot] imx27lite stability problems.

[Fred Fan]

Dear Javier Martin:

2009/9/17, javier Martin <javier.martin@vista-silicon.com>:
>
> I've found some problems because the cache is enabled, I don't see any
> place where you disable it.
> [Fred] Do you means D-cache is enabled? There are no mmu enabled, D-cache
> should be disabled as default setting.

IAre you sure you have this controlled properly?

--
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com
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[U-Boot] imx27lite stability problems.

[javier Martin]

2009/9/17 Fred Fan <fanyefeng@gmail.com>:
> Dear Javier Martin:
>
> 2009/9/17, javier Martin <javier.martin@vista-silicon.com>:
>>
>> I've found some problems because the cache is enabled, I don't see any
>> place where you disable it.
>> [Fred] Do you means D-cache is enabled? There are no mmu enabled, D-cache
>> should be disabled as default setting.

This is what I also though but I found it making some debugging
through JTAG + GDB.

As I stated in my first mail, FEC driver was getting stuck after
transmitting a frame in a while() loop. However, using wireshark the
frame had actually been sent. And using GDB I found that in the SDRAM
the while() condition was true, nevertheless the microprocessor was
evaluating it as false. That seemed to cache issues to me, so I put a
"dcache_disable()" just before that while() loop and saw that these
problems were not happening anymore.

What is your opinion?
Thanks.

-- 
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com

[U-Boot] imx27lite stability problems.

[javier Martin]

2009/9/17 Wolfgang Denk <wd@denx.de>:
> Dear javier Martin
>
>> I would like to help to solve this problems, but I don't know exactly
>> where to begin from. I have been reviewing clock settings. Could this
>> be happening because this board is using 32KHz xtal as reference
>> instead of 26MHz one?
>
> Yes, of course this could be a problem. Is this an original LogicPD
> board? ?Did you adapt the code for the different clock speed? What
> exactly did you change?

Dear Wolfgang Denk,
I could finally test this in an original LogicPD i.mx27 litekit board
and found the same problems.
System gets stuck when issuing a ping command.

- I am using u-boot-arm repository "commit
617da90c1dcf65428ddfb63fef897439950bc915" without any modifications.
- arm-linux-gcc toolchains from eldk-arm-4.1.
- I configured u-boot for i.mx27 litekit, compiled and flashed it in
the NOR with a JTAG.


Please, do you have an idea of what could I be missing?


-- 
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com

[U-Boot] imx27lite stability problems.

[Wolfgang Denk]

Dear Javier Martin,

In message <eedb5540910160633o81b1ae3sf37b2a00a5474584@mail.gmail.com> you wrote:
>
> I could finally test this in an original LogicPD i.mx27 litekit board
> and found the same problems.
> System gets stuck when issuing a ping command.
> 
> - I am using u-boot-arm repository "commit
> 617da90c1dcf65428ddfb63fef897439950bc915" without any modifications.

Can you please use mainline, i. e. the master branch at
git://git.denx.de/u-boot.git instead?

> Please, do you have an idea of what could I be missing?

Well, there is a "Possible iMX27 intermittent Ethernet connection
issue rework" issued by LPD on 7/8/2008; in essence the PHY's
internal 1.8V core regulator may shut off at power up.

To work around this, try and implement the following two hardware
modifications:

1) Populate R841 with a 4.7K resistor. (This forces the internal core
   regulator off for the LAN8700. R841 is located on top of the PCB
   just "above" the LAN8700 IC.

2) Add a jumper wire from U125.5 to C561.1. This connects the on
   board 1.8V rail to the core ensuring that it is always powered.


And no, I don't guarantee you for anything.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Parkinson's Law:  Work expands to fill the time alloted it.

[U-Boot] imx27lite stability problems.

[javier Martin]

2009/10/16 Wolfgang Denk <wd@denx.de>:
> Dear Javier Martin,
>
> In message <eedb5540910160633o81b1ae3sf37b2a00a5474584@mail.gmail.com> you wrote:
>>
>> I could finally test this in an original LogicPD i.mx27 litekit board
>> and found the same problems.
>> System gets stuck when issuing a ping command.
>>
>> - I am using u-boot-arm repository "commit
>> 617da90c1dcf65428ddfb63fef897439950bc915" without any modifications.
>
> Can you please use mainline, i. e. the master branch at
> git://git.denx.de/u-boot.git instead?
>
>> Please, do you have an idea of what could I be missing?
>
> Well, there is a "Possible iMX27 intermittent Ethernet connection
> issue rework" issued by LPD on 7/8/2008; in essence the PHY's
> internal 1.8V core regulator may shut off at power up.
>
> To work around this, try and implement the following two hardware
> modifications:
>
> 1) Populate R841 with a 4.7K resistor. (This forces the internal core
> ? regulator off for the LAN8700. R841 is located on top of the PCB
> ? just "above" the LAN8700 IC.
>
> 2) Add a jumper wire from U125.5 to C561.1. This connects the on
> ? board 1.8V rail to the core ensuring that it is always powered.


Before trying hardware fixes you suggested I tried using another
toolchain which comes with LTIB for i.mx27ads:

* I used arm-linux-gnueabi- toolchain from LTIB with the command:

USE_PRIVATE_LIBGCC=yes make  CROSS_COMPILE=arm-none-linux-gnueabi-

And found some improvements, ping doesn't hang the system, although it
fails, but the second time it is executed I get an error:

=> ping 192.168.0.40
FEC_MXC: Autonegotiation timeout
Using FEC_MXC device
ping failed; host 192.168.0.40 is not alive

=> ping 192.168.0.40

Unhandled Exception:
exception mode: abort
fsr: 0x00000008 far: 0x0000000c

**UNRECOVERABLE ERROR**
There was a memory access exception at 0x0000000c of type 'extern fetch1'
this may be due to an access to an invalid memory region,
unaligned access, or a problem with the current memory map.
Please check the memory layout section of your processor manual.
For information about the active memory map type 'info cpu'.

r00: a7e9c000 r01: 00000000 r02: 00000000 r03: 00000000
r04: a7e816f8 r05: a7e81700 r06: 00000000 r07: a7f31600
r08: a7e6ffe0 r09: 00000000 r10: 00000000 r11: 00000000
r12: a7f326f0 sp:  a7e6f270 lr:  0001a908  pc: a7f1774c
spsr:000000d3 cpsr:000000d7
bt: sp: a7e6f1a8 (stack: a00667e4 - a00697e4)
(fp:00000000->a7e6f1d0, sp:a7e6f1a8)

What toolchain are you using for compiling this? It seems I got a
different behavior changing it.

-- 
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com

[U-Boot] imx27lite stability problems.

[Wolfgang Denk]

Dear Javier Martin,

In message <eedb5540910190020t37a29377mdd5d56a6f33679af@mail.gmail.com> you wrote:
>
> Before trying hardware fixes you suggested I tried using another
> toolchain which comes with LTIB for i.mx27ads:

You may want to contact LPD support; eventually they replace your
board with a working one.

> * I used arm-linux-gnueabi- toolchain from LTIB with the command:
...
> And found some improvements, ping doesn't hang the system, although it
> fails, but the second time it is executed I get an error:
...
> What toolchain are you using for compiling this? It seems I got a
> different behavior changing it.

We are using ELDK.

Your test may indicate another issue (with the tool chain). Note that
we saw different manifestations of this problem: some boards worked
perfectly fine (no error ever), others failed always, one was workign
or failing depending on temperature, phase of moon and other unknown
factors.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"Intelligence without character is a dangerous thing."   - G. Steinem