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

Marek Vasut
2016-11-01T20:42:10Z

On 11/01/2016 09:39 PM, Dinh Nguyen wrote:
>
>
> On 11/01/2016 03:09 PM, Marek Vasut wrote:
>> 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 ?
>>
>
> Okay, I can check it on the SoCKit.

It also happens on MCVEVK, but that's probably moot for your test ;-)

--
Best regards,
Marek Vasut