Re: [PATCH v7 0/5] Add driver for EC found on Qualcomm reference devices

[Rob Clark]

On Sun, Mar 29, 2026 at 11:57 PM Anvesh Jain P
<anvesh.p@xxxxxxxxxxxxxxxx> wrote:
>
>
>
> On 3/29/2026 7:52 PM, Akhil P Oommen wrote:
> > On 3/27/2026 3:38 PM, Anvesh Jain P wrote:
> >> From: Anvesh Jain P <anvesh.p@xxxxxxxxxxxxxxxx>
> >>
> >> Add Embedded controller driver support for Hamoa/Purwa/Glymur Qualcomm
> >> reference boards. It handles fan control, temperature sensors, access
> >> to EC state changes and supports reporting suspend entry/exit to the EC.
> >
> > Just a question, is it possible to force fan to run at full speed
> > constantly? That would be helpful to keep the passive cooling minimal
> > and get a more consistent results while doing performance profiling.
> >
> > I see that you are registering a cooling device in this series. So I
> > suppose we just need to update the cooling sysfs nodes.
> >
> > -Akhil
> >
>
> Hi Akhil,
>
> Yes, that is possible. The cooling device registered by this driver
> exposes the standard thermal sysfs interface. You can force the fan
> to full speed by writing the maximum cooling state directly:
>
>   # Find the max state
>   cat /sys/class/thermal/cooling_deviceX/max_state
>
>   # Set to max state (force full speed)
>   echo <max_state> > /sys/class/thermal/cooling_deviceX/cur_state
>
> Where X is the index of the cooling device corresponding to the EC fan.

Getting a bit off topic, but is there a good way to associated cooling
devices and thermal sensors to the GPU device?  I could see that being
useful for nvtop (which currently supports shows GPU load and memory
metrics, but thermal metrics are missing for us)

BR,
-R

> --
> Best Regards,
> Anvesh
>
>