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

Marek Vasut marex at denx.de
Fri Nov 4 21:56:55 CET 2016


On 11/03/2016 03:21 PM, Dinh Nguyen wrote:
> 
> 
> On 11/02/2016 03:47 PM, Marek Vasut wrote:
>> On 11/02/2016 05:30 PM, Dinh Nguyen wrote:
>>> On Tue, Nov 1, 2016 at 3:43 PM, Dinh Nguyen <dinguyen at kernel.org> wrote:
>>>>
>>>>
>>>> On 11/01/2016 03:42 PM, Marek Vasut wrote:
>>>>> 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 at 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 ;-)
>>>>>
>>>>
>>>> I don't have an MCVEVK.
>>>>
>>>
>>> The "reset" functionality is working fine on the SoCKit with 2016.11-rc3.
>>
>> Does it work on 2016.09.01 too ?
>>
> 
> Yes...reset works fine on 2016.09.01 and 2016.09 on my SoCKit.
> 
> Dinh
> 
Well it doesn't work on mine ... compiler problem ?

-- 
Best regards,
Marek Vasut


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