Re: [PATCH v4 00/19] Enable GPU with DVFS support on MediaTek SoCs

From: AngeloGioacchino Del Regno
Date: Tue Mar 07 2023 - 04:37:25 EST


Il 07/03/23 10:27, Chen-Yu Tsai ha scritto:
On Thu, Mar 2, 2023 at 7:28 PM Matthias Brugger <matthias.bgg@xxxxxxxxx> wrote:
On 02/03/2023 11:11, Chen-Yu Tsai wrote:
On Thu, Mar 2, 2023 at 6:10 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:

Il 02/03/23 10:36, Matthias Brugger ha scritto:
Series looks good but from my understanding has a dependency on:
[PATCH v4 00/12] Panfrost: Improve and add MediaTek SoCs support
(https://lore.kernel.org/linux-mediatek/20230228102610.707605-1-angelogioacchino.delregno@xxxxxxxxxxxxx/)

Did I get that right?


Yes you got it right - without the mentioned series, this one will do nothing
at all (and will also fail binding checks, as the bindings are introduced in
that other series).

Please also let me test them on MT8183 and MT8186 before merging them.


Of course, I'll wait for your tested-by tags then.
Thanks for testing!

Tested-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>

on MT8183, MT8186, MT8192 and MT8195 Chromebooks.

BTW, Angelo, I see that Panfrost keeps the GPU regulator enabled, but
the power domains, and thus the SRAM regulator, get powered off when
the GPU is not in use. There doesn't seem to be any damaging effects,
but I worry about idle power consumption.

ChenYu

Yes I've seen that as well... and it's true there will be some unwanted
small power leakage.

Though, I would propose to do things step by step. Right now, as it is, the
platform is fully stable... so let's get this in so that we estabilish a
known working baseline... what I have in mind is, exactly:

1. Get Panfrost+DVFS working on current platforms; then
2. Resolve the GPU binning situation (eFuses -> opp-supported-hw)
3. Improve the power consumption (all GPU regulators off during suspend)

Thanks for all the valuable testing and support!

Cheers,
Angelo