Re: [PATCH] PCI: qcom: Power on pwrctrl devices for firmware-managed hosts

[Zhangfei Gao]

On Thu, Nov 5, 2026 at 10:37 PM Manivannan Sadhasivam <mani@xxxxxxxxxx> wrote:
>
> On Thu, Nov 05, 2026 at 06:15:21PM +0800, Zhangfei Gao wrote:
> > commit b921aa3f8dec ("PCI/pwrctrl: Switch to pwrctrl create, power
> > on/off, destroy APIs") switched PCI pwrctrl users to explicit create and
> > power control APIs, but only added the calls to the regular DesignWare
> > host initialization path.
> >
> > Firmware-managed hosts bypass that path and probe the ECAM host bridge
> > directly. Endpoints already powered by firmware, such as NVMe devices,
> > remain discoverable. Endpoints that rely on Linux pwrctrl and pwrseq,
> > such as WCN7850, remain powered off and cannot be discovered.
> >
>
> NACK. For FW initialized platforms, FW should power on the Endpoints before
> booting Linux.

Thanks Mani for the clarification.

  To confirm, for a firmware-initialized PCIe host, is the platform
  firmware expected to perform the complete board-level Endpoint power
  sequence as well, rather than only initializing the PCIe controller?

  On this platform, WCN7850 requires PMAU0102-E GPIOs 6/7/8 to enable its
  power rails and GPIO10 for WLAN_EN. Should firmware assert these GPIOs
  before Linux probes the ECAM host bridge and keep the Endpoint powered,
  including across suspend/resume as appropriate?

  If so, we will drop this driver change and coordinate the required
  platform firmware update.

Thanks