Re: [PATCH v3 0/3] clk: qcom: gcc-glymur: Tie the CX power domain to controller

[Abel Vesa]

On 26-08-24 11:12:53, Rajendra Nayak wrote:
> 
> 
> On 8/21/2026 4:04 PM, Pankaj Patil wrote:
> > On 8/17/2026 3:40 PM, Konrad Dybcio wrote:
> > > On 8/14/26 8:30 AM, Pankaj Patil wrote:
> > > > On 7/15/2026 6:59 PM, Abel Vesa wrote:
> > > > > The suggestion of having the CX power domain tied up to the GCC
> > > > > controller started here:
> > > > > 
> > > > > https://lore.kernel.org/lkml/fe210f0b-692b-4c45-afc4-fc2bc5e57854@xxxxxxxxxxxxxxxx/
> > > > > 
> > > > > and then, for Glymur, it has been brought up here as well:
> > > > > 
> > > > > https://lore.kernel.org/all/0248dc51-1036-426c-b1de-dbc71696e2c1@xxxxxxxxxxxxxxxx/
> > > > > 
> > > > > These plus a discussion off-list led to this patchset being done.
> > > > > 
> > > > 
> > > > This series prevents cx collapse during suspend on recent linux-next tag: next-20260806
> > > > Reproducible on latest tag next-20260813 as well
> > > 
> > > Yes and the ""fix"" is to disable the GPU nodes because the custom
> > > runtime pm dance done in the gxclkctl driver keeps a vote online
> > > 
> > > That should be fixed instead
> > > 
> > > FWIW ath12k is causing some issues for me in this regard too..
> > > 
> > > Konrad
> > 
> > There's no need to disable gpu nodes for cx collapse on s2idle, I can reach cx
> > collapse after disabling crypto, camcc and evacc nodes along with reverting
> > this series, Specifically arm64: dts: qcom: glymur: Add CX power domain to GCC
> > Can you share the steps to reproduce? Are you running additional steps before
> > triggering suspend?
> 
> GCC clock driver on Glymur has gcc_disp_hf_axi_clk marked as
> CLK_IS_CRITICAL, doesn't that mean we will always have a vote on CX
> with this patch?

Marking a clock as critical does not imply holding a vote on CX here.

CLK_IS_CRITICAL only prevents CCF from gating the clock through the normal
clock disable path. It does not hold a runtime PM reference on the GCC
device, and therefore does not by itself keep CX on.

Once the consumers have been suspended, GCC itself can be suspended and CX
can collapse. At that point the critical clock may stop ticking as a
consequence of the controller/domain being powered down, without affecting
any active consumers.