Re: [Nouveau] [PATCH nouveau 09/11] drm: export some variable and functions to resue the PM functions

[Vince Hsu <vinceh@nvidia.com>]

On 01/06/2015 07:49 PM, Thierry Reding wrote:
> * PGP Signed by an unknown key
>
> On Mon, Jan 05, 2015 at 08:50:18PM +0100, Alexandre Courbot wrote:
>> On Mon, Jan 5, 2015 at 4:32 PM, Thierry Reding <thierry.reding@gmail.com> wrote:
>>> On Tue, Dec 30, 2014 at 11:18:34AM +0800, Vince Hsu wrote:
>>>> Hi Emil,
>>>>
>>>> On 12/30/2014 10:34 AM, Emil Velikov wrote:
>>>>> On 23/12/14 10:40, Vince Hsu wrote:
>>>>>> This patch adds some checks in the suspend/resume functions to distinguish
>>>>>> the dGPU and mobile GPU and exports some variables/functions so that the
>>>>>> nouveau platform device can reuse them.
>>>>>>
>>>>> Hi Vince,
>>>>>
>>>>> Afaiu one needs to export a symbol as it's used by another module or
>>>>> subsystem. With the follow up two patches you are not doing either one,
>>>>> so I'd assume that you can just omit the EXPORT_* changes.
>>>> The nouveau platform device driver is built as another module -
>>>> nouveau_platform.ko. :)
>>> I'd like to hear the opinion of the nouveau people and Alex, but I'd
>>> very much prefer if nouveau_platform.o was simply linked into the
>>> nouveau.ko module. I don't see any good reason to keep it separate.
>> Yep, I agree. The decision to host platform support in a separate
>> module looks misleaded if it results in additional exports that we
>> would otherwise avoid. IIUC I did this to be able to use the module
>> convenience macros to register the platform driver.
>>
>>> Something like the attached patch (untested) ought to do it.
>> This patch alone won't be enough for the reason I mentioned above.
>> However, if Vince doesn't mind handling the platform driver
>> registration manually in nouveau_drm_init/nouveau_drm_exit, I agree
>> this would be the way to go.
> If we do the conversion to generic power domains, the only Tegra-
> specific API remaining will be the access to the fuse registers for the
> speedo value. At that point we wouldn't need the ARCH_TEGRA dependency
> any longer and could always build the platform driver along with the PCI
> driver.
Do we really want the platform driver always built with the PCI driver even
there is no dependency between them. Actually I have some patches to
build the platform driver with !CONFIG_PCI and would like to post them maybe
later.

Thanks,
Vince

>
> I guess we could do that even now if we simply #ifdef the various Tegra-
> specific parts. That in turn would have the advantage that we don't need
> to #ifdef the driver registration code. And it would help separate
> things in case anybody wanted to use one of the SoC GPUs in a non-Tegra
> SoC.