Re: [PATCH] ARM: davinci_all_defconfig: enable CMA options

[Sekhar Nori <nsekhar@ti.com>]

Hi David,

On Friday 22 September 2017 10:13 PM, David Lechner wrote:
> On 09/22/2017 11:24 AM, Suman Anna wrote:
>> Hi Sekhar,
>>
>>>
>>> On Thursday 21 September 2017 08:41 PM, Suman Anna wrote:
>>>> On 09/21/2017 09:43 AM, Sekhar Nori wrote:
>>>>> On Wednesday 20 September 2017 11:31 PM, Suman Anna wrote:
>>>>>> Enable the CMA and DMA_CMA Kconfig options by default for
>>>>>> Davinci platforms. Davinci remoteproc driver is one of the
>>>>>> modules that depends on these options, and this allows the
>>>>>> driver to be made visible for selection with menuconfig.
>>>>>>
>>>>>> Signed-off-by: Suman Anna <s-anna@ti.com>
>>>>>> ---
>>>>>> Hi Sekhar,
>>>>>>
>>>>>> Here's the patch that enables CMA as per your request. Patch based
>>>>>> on your v4.15/defconfig branch.
>>>>>
>>>>> Applied! I guess you will be sending another patch enabling the
>>>>> remoteproc driver itself?
>>>>
>>>> Thanks. Well, one always needs a firmware image in their filesystem
>>>> without which enabling the driver is meaningless (it would fail). So
>>>> was
>>>> not planning to enable it by default.
>>>
>>> But the errors will show up only on DA850 LCDK where we have enabled the
>>> DSP by default in DT because its an important usecase there. I think it
>>> is important for users to see those errors.
>>> (besides the usual benefits of having the module enabled to catch build
>>> and runtime issues easily).
>>
>> Yeah, DSP node is enabled only for DA850 LCDK among the DT-supported
>> boards, but I believe there are boards still using legacy boot, and it
>> shows up on those platforms as well. FYI, we do not have any rpmsg
>> drivers other than the kernel sample to make real usage of a booted
>> remoteproc. Anycase, if you still prefer this to be added, I don't mind.
>>
>> regards
>> Suman
>>
> 
> I am interested in using remoteproc on LEGO MINDSTORMS EV3 to implement
> I2C and UART in the PRU.

Do note that the remoteproc driver being discussed here is the DSP
remoteproc driver. TI releases have a remoteproc driver that talks to
PRUSS[1], but that has not been used to talk to PRUSS on OMAP-L138. And
AFAIK, there is no one working towards that in TI as well.

Thanks,
Sekhar

[1]
http://git.ti.com/cgit/cgit.cgi/ti-linux-kernel/ti-linux-kernel.git/tree/drivers/remoteproc/pru_rproc.c?h=ti-linux-4.9.y