[U-Boot] [PATCH 11/13] x86: baytrail: Issue full system reset in reset_cpu()

[Bin Meng]

Hi Simon,

On Mon, Oct 19, 2015 at 4:27 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 11 October 2015 at 22:37, Bin Meng <bmeng.cn at gmail.com> wrote:
>> With MRC cache enabled, when typing 'reset' in the U-Boot shell,
>> BayTrail FSP initialization hangs at "Configuring Memory Start":
>>
>>   Setting BootMode to 0
>>   Install PPI: 1F4C6F90-B06B-48D8-A201-BAE5F1CD7D56
>>   Register PPI Notify: F894643D-C449-42D1-8EA8-85BDD8C65BDE
>>   About to call MrcInit();
>>   BayleyBay Platform Type
>>   CurrentMrcData.BootMode = 4
>>   Taking Fastboot path!
>>   Configuring Memory Start...
>>
>> Changing reset_cpu() to do a full system reset fixes this issue.
>>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>
>>  arch/x86/cpu/baytrail/valleyview.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>
> Acked-by: Simon Glass <sjg at chromium.org>
>
>>
>> diff --git a/arch/x86/cpu/baytrail/valleyview.c b/arch/x86/cpu/baytrail/valleyview.c
>> index 215e0d0..a009c14 100644
>> --- a/arch/x86/cpu/baytrail/valleyview.c
>> +++ b/arch/x86/cpu/baytrail/valleyview.c
>> @@ -65,3 +65,9 @@ int reserve_arch(void)
>>  #endif
>>  }
>>  #endif
>> +
>> +void reset_cpu(ulong addr)
>> +{
>> +       /* cold reset */
>> +       x86_full_reset();
>> +}
>> --
>> 1.8.2.1
>>
>
> Actually on Minnowmax this doesn't fix the hang.

That's strange. As full reset indicates a complete power cycle. Does
MinnowMax boot with MRC cache enabled?

>
> Also I don't see any speed-up from using the cache on Minnowmax.

On Galileo, I did not see any speed-up either. I think it is because
on MinnowMax and Galileo they both uses memory-down configuration. The
speed-up seems only helpful for DIMMs (on Intel Bayley Bay)

>
> Regards,
> Simon

Regards,
Bin