[U-Boot] [PATCH] arm: socfpga: dm: Fix DM initialization failure after warm reset

[Jian Luo <Jian.Luo4@boschrexroth.de>]

On 28.08.2015 12:30, Marek Vasut wrote:
> On Friday, August 28, 2015 at 12:27:18 PM, Jian Luo wrote:
>> Hi Marek,
>>
>> On 28.08.2015 11:24, Marek Vasut wrote:
>>> On Friday, August 28, 2015 at 10:41:50 AM, Jian Luo wrote:
>>>> gd->dm_root is not cleared in SPL after warm reset.
>>>> This might cause DM initilazation failure.
>>>>
>>>> Signed-off-by: Jian Luo <jian.luo4@boschrexroth.de>
>>> Hi!
>>>
>>>> ---
>>>>
>>>>     arch/arm/mach-socfpga/spl.c | 6 ++++++
>>>>     1 file changed, 6 insertions(+)
>>>>
>>>> diff --git a/arch/arm/mach-socfpga/spl.c b/arch/arm/mach-socfpga/spl.c
>>>> index 13ec24b..59fe1f2 100644
>>>> --- a/arch/arm/mach-socfpga/spl.c
>>>> +++ b/arch/arm/mach-socfpga/spl.c
>>>> @@ -181,5 +181,11 @@ void board_init_f(ulong dummy)
>>>>
>>>>            /* Configure simple malloc base pointer into RAM. */
>>>>            gd->malloc_base = CONFIG_SYS_TEXT_BASE + (1024 * 1024);
>>>>
>>>> +       /*
>>>> +        * gd->dm_root might contain non-zero value after warm reset.
>>>> +        * Clear it to avoid dm_init error
>>>> +        */
>>>> +       gd->dm_root = NULL;
>>> Nit: The indent should be done with tabs, not spaces. I think the email
>>> got messed up somewhere along the way.
>> Yes, sorry. I can't setup git send-email in our company network.
>> Thunderbird messed the indent up.
> Why not ?
"Security policy". :(
>
>>> The bigger concern I have is that if you look into arch/arm/lib/crt0.S ,
>>> you will see that the entire global data are cleared there (_main, label
>>> clr_gd: ) and this code is executed before the board_init_f() .
>> This was my first assumption, it should be cleared in crt0.S.
>> I was using U-Boot to load a VxWorks image.
>> And wrote 1 to rstmgr ctrl in VxWorks to do a warm reset.
>> Afterwards the SPL hangs.
> Hangs in which way ? Can you share the output please ?
Sorry, should attached the output in the first place.
With CONFIG_DM_WARN defined:

*************************
***** VxWorks is up *****
*************************

-> reboot

U-Boot SPL 2015.10-rc2-00192-ge122af6-dirty (Aug 28 2015 - 11:35:27)
drivers/ddr/altera/sequencer.c: Preparing to start memory calibration
drivers/ddr/altera/sequencer.c: CALIBRATION PASSED
drivers/ddr/altera/sequencer.c: Calibration complete
Virtual root driver already exists!
### ERROR ### Please RESET the board ###


>
>> It did not happen if I do reset direct in U-Boot.
>> I'll attach a JTAG Debug to dig deeper.
> Neat, that'd be really awesome, thanks for looking into this !
>
>>> Can you try tracking it down a bit more? I suspect that you might see
>>> dm_init_and_scan() returned error -22 , is that what you observe please?
>> Yes, in dm_init() where gd->dm_root will be checked.
> But if you get -ENOMEM, that means somehow the malloc is broken here.
> I wonder if this explicit setting of gd->malloc_area is screwing something
> up ?
Isn't 22 EINVAL?
It's in the drivers/core/root.c line 105
>
> Best regards,
> Marek Vasut
Best regards,

Jian Luo
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