[yocto] [meta-raspberrypi][PATCH v2 4/4] README: Add a section about graphic stacks

[Andreas Müller]

On Wed, Oct 21, 2015 at 3:48 PM, Javier Martinez Canillas
<javier at osg.samsung.com> wrote:
> Hello Andrei,
>
> On 10/21/2015 02:32 PM, Andrei Gherzan wrote:
>> Hello Javier,
>>
>> On Mon, Aug 24, 2015 at 10:25:30PM +0200, Javier Martinez Canillas wrote:
>>> Hello,
>>>
>>> On 08/17/2015 11:58 AM, Javier Martinez Canillas wrote:
>>>> On 08/17/2015 09:57 AM, Andrei Gherzan wrote:
>>>>> On Thursday, August 13, 2015, Khem Raj <raj.khem at gmail.com> wrote:
>>>
>>> [snip]
>>>
>>>>>>>
>>>>>>> +2.O. Graphic stacks
>>>>>>> +===================
>>>>>>> +The Raspberry Pi boards can use one of two graphics stacks: The userland
>>>>>>> +user-space driver or the vc4 DRM/KMS kernel driver. By default userland
>>>>>>> +is used since the vc4 is still experimental. But this can be changed by
>>>>>>> +modifying the defaults for the kernel, egl, gles2, libgl and mesa
>>>>>> providers.
>>>>>>> +This is explained in the conf/machine/include/rpi-default-providers.inc
>>>>>> file.
>>>>>>> +
>>>>>>
>>>>>> you may want to add pointer to the commented out code that you have added
>>>>>> to select them
>>>>>> in rpi-default-providers.inc
>>>>>>
>>>>>
>>>>> It would be nice to have some detailed info on what and where to comment
>>>>> out the configuration.
>>>>>
>>>>
>>>> On patch 3/4 I added that documentation to rpi-default-providers but didn't
>>>> add it to the README and instead pointed out to rpi-default-providers to
>>>> have a level of indirection in case the providers change and to not have
>>>> duplicated information but I will add it to the README as well.
>>>>
>>>> Do you have comments on the other patches in the series so I can address
>>>> all of them before re-spinning?
>>>>
>>>
>>
>> Really sorry on this late reply. So my only recommendation is to move things
>
> No worries, I've also been very busy with other stuff.
>
>> you wrote in 3/4 in the 4/4 (README). Basically you would describe what a user
>> needs to overwrite as providers in order to use VC4 as graphics stack.
>>
>
> Ok, I'm traveling to Korea next week for KLF and KS so I'll probably resend
> a v3 (addressing your suggestions) later next week when I'm back.
>
>> As well, how do you handle the devicetrees for 4.1? Aren't changed in 4+?
>>
>
> For now, I'm defining a KERNEL_DEVICETREE in my conf/local.conf file since
> that is what was agreed with Petter Mabäcker on v1 of this series [0 and
> I also mentioned in the cover letter [1].
>
> But the new device tree overlay dir layout is not only for 4+ but also it
> is used in the latest version of the older branches. So once all recipes'
> SRCREV are bumped, overwriting the variable won't be necessary anymore.
>
>>> Gentle ping about this. Thanks!
>>>
>>> Best regards,
>>> --
>>> Javier Martinez Canillas
>>> Open Source Group
>>> Samsung Research America
>>
>> --
>> Andrei Gherzan
>>
>
> [0]: https://lists.yoctoproject.org/pipermail/yocto/2015-August/025961.html
> [1]: https://lists.yoctoproject.org/pipermail/yocto/2015-August/026151.html
>
> Best regards,
> --
> Javier Martinez Canillas
> Open Source Group
> Samsung Research America
When reworking: If I am not mistaken there is a chance that
modesetting will work when using latest kernel versions from Eric
Anholt. So would you mind to rebase the patches to these changes? I
would again play tester role.

Andreas