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

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

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.
> 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.

It did not happen if I do reset direct in U-Boot.
I'll attach a JTAG Debug to dig deeper.
> 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.
>
>>           board_init_r(NULL, 0);
>>    }
> Best regards,
> Marek Vasut


Best regards,

Jian Luo