Re: [PATCH v8 7/8] thermal: Add PCIe cooling driver
From: Jonathan Cameron
Date: Thu Oct 17 2024 - 07:05:14 EST
On Wed, 9 Oct 2024 12:52:22 +0300
Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote:
> Add a thermal cooling driver to provide path to access PCIe bandwidth
> controller using the usual thermal interfaces.
>
> A cooling device is instantiated for controllable PCIe Ports from the
> bwctrl service driver.
>
> If registering the cooling device fails, allow bwctrl's probe to
> succeed regardless. As cdev in that case contains IS_ERR() pseudo
> "pointer", clean that up inside the probe function so the remove side
> doesn't need to suddenly make an odd looking IS_ERR() check.
>
> The thermal side state 0 means no throttling, i.e., maximum supported
> PCIe Link Speed.
>
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx> # From the cooling device interface perspective
Trivial thing noticed on a reread.
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 61e7ae524b1f..d3f9686e26e7 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -220,6 +220,15 @@ config DEVFREQ_THERMAL
>
> If you want this support, you should say Y here.
>
> +config PCIE_THERMAL
> + bool "PCIe cooling support"
> + depends on PCIEPORTBUS
> + help
> + This implements PCIe cooling mechanism through bandwidth reduction
> + for PCIe devices.
Technically links not devices, but don't think that matters much