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

[Anvesh Jain P <anvesh.p@oss.qualcomm.com>]

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@oss.qualcomm.com>
>>
>> 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.

-- 
Best Regards,
Anvesh