[lkml]   [2015]   [Jan]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 1/11] ARM: tegra: add function to control the GPU rail clamp
On Thu, Dec 25, 2014 at 10:28:08AM +0800, Vince Hsu wrote:
> On 12/24/2014 09:16 PM, Lucas Stach wrote:
> >Am Dienstag, den 23.12.2014, 18:39 +0800 schrieb Vince Hsu:
> >>The Tegra124 and later Tegra SoCs have a sepatate rail gating register
> >>to enable/disable the clamp. The original function
> >>tegra_powergate_remove_clamping() is not sufficient for the enable
> >>function. So add a new function which is dedicated to the GPU rail
> >>gating. Also don't refer to the powergate ID since the GPU ID makes no
> >>sense here.
> >>
> >>Signed-off-by: Vince Hsu <>
> >To be honest I don't see the point of this patch.
> >You are bloating the PMC interface by introducing another exported
> >function that does nothing different than what the current function
> >already does.
> >
> >If you need a way to assert the clamp I would have expected you to
> >introduce a common function to do this for all power partitions.
> I thought about adding an tegra_powergate_assert_clamping(), but that
> doesn't make sense to all the power partitions except GPU. Note the
> difference in TRM. Any suggestion for the common function?

I don't think extending the powergate API is useful at this point. We've
long had an open TODO item to replace this with a generic API. I did
some prototyping a while ago to use generic power domains for this, that
way all the details and dependencies between the partitions could be
properly modeled.

Can you take a look at my staging/powergate branch here:

and see if you can use that instead? The idea is to completely hide the
details of power partitions from drivers and use runtime PM instead.

Also adding Peter whom I had discussed this with earlier. Can we finally
get this converted? I'd rather not keep complicating this custom API to
avoid making the conversion even more difficult.

[unhandled content-type:application/pgp-signature]
 \ /
  Last update: 2015-01-05 16:41    [W:0.228 / U:0.572 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site