Re: [PATCH 2/2] usb: typec: ucsi: Don't create power supplies for dGPUs

From: Andy Shevchenko
Date: Wed May 17 2023 - 13:14:25 EST


On Tue, May 16, 2023 at 01:25:41PM -0500, Mario Limonciello wrote:
> power_supply_is_system_supplied() checks whether any power
> supplies are present that aren't batteries to decide whether
> the system is running on DC or AC. Downstream drivers use
> this to make performance decisions.
>
> Navi dGPUs include an UCSI function that has been exported
> since commit 17631e8ca2d3 ("i2c: designware: Add driver
> support for AMD NAVI GPU").
>
> This UCSI function registers a power supply since commit
> 992a60ed0d5e ("usb: typec: ucsi: register with power_supply class")
> but this is not a system power supply.
>
> As the power supply for a dGPU is only for powering devices connected
> to dGPU, create a device property to indicate that the UCSI endpoint
> is only for the scope of `POWER_SUPPLY_SCOPE_DEVICE`.

...

> +static const struct property_entry dgpu_properties[] = {
> + /* USB-C doesn't power the system */
> + PROPERTY_ENTRY_U8("scope", POWER_SUPPLY_SCOPE_DEVICE),
> + {},

Comma is not needed in terminator entry.

> +};

--
With Best Regards,
Andy Shevchenko