[U-Boot] [RFC] 0/4] Add Pl330 DMA support

Marek Vasut
2016-11-01T20:09:17Z

On 11/01/2016 04:43 PM, Dinh Nguyen wrote:
>
>
> On 10/29/2016 02:59 PM, Marek Vasut wrote:
>> On 10/18/2016 05:50 PM, Dinh Nguyen wrote:
>>> On Sun, Oct 16, 2016 at 10:59 AM, Marek Vasut <marex@denx.de> wrote:
>>>> On 10/15/2016 12:10 AM, Dinh Nguyen wrote:
>>>>>
>>>>>
>>>>> On 10/10/2016 10:52 AM, Dinh Nguyen wrote:
>>>>>> Hi,
>>>>>>
>>>>>> This patchset adds the PL330 DMA driver to U-Boot. The SoCFPGA platform makes
>>>>>> use of the PL330 to transfer zereos to the SDRAM which enables the ECC bit.
>>>>>>
>>>>>> This is only an RFC because after rebasing to v2016.11-rc1, I had to revert
>>>>>> the following patch "a78cd8613204 ARM: Rework and correct barrier definitions"
>>>>>> in order for this patch set to work correctly. With the above patch applied,
>>>>>> after the SDRAM scrubbing is complete, the SPL is failing to find the MMC
>>>>>> device.
>>>>>>
>>>>>
>>>>> I kinda figured out why patch "a78cd8613204 ARM: Rework and correct
>>>>> barrier definitions" is causing SPL to fail after the SDRAM scrub
>>>>> operation. It appears that before the above mentioned patch, the dmb()
>>>>> operation is defined as this:
>>>>>
>>>>> #define dmb() __asm__ __volatile__ ("" : : : "memory")
>>>>>
>>>>> after the patch, the dmb is now:
>>>>>
>>>>> #define DMB asm volatile ("dmb sy" : : : "memory")
>>>>>
>>>>> So the "dmb sy" as described in the ARM documentation is a "Full system
>>>>> DMB operation". For whatever reason, this change is causing the SPL
>>>>> error after the SDRAM scrub operation.
>>>>
>>>> Thanks for looking into this, can you poke into it some more ?
>>>>
>>>
>>> Of course..
>>
>> The patch is causing a failure even in normal operation -- if you boot
>> the socfpga board and type "reset", it won't reset with the patch.
>>
>
> Can I ask what board are you seeing this on? I'm seeing that on my Atlas
> board, it does not reset properly(even with the patch reverted). But
> "reset" is working fine on my devkit, with and without the patch.

SoCKit and MCVEVK.

I tried bisecting it, it worked on 2016.07 and doesn't on 2016.09 , and
I arrived at this patch. Maybe you can double-check this ?

--
Best regards,
Marek Vasut