Re: (subset) [PATCH v3 0/4] PCI/pwrctrl: Allow pwrctrl framework to control PERST# if available

From: Manivannan Sadhasivam

Date: Wed Sep 17 2025 - 06:10:53 EST



On Fri, 12 Sep 2025 14:05:00 +0530, Manivannan Sadhasivam wrote:
> This series is the proper version for toggling PERST# from the pwrctrl
> framework after the initial RFC posted earlier [1].
>
> Problem statement
> =================
>
> Pwrctrl framework is intented to control the supplies to the components on the
> PCI bus. However, if the platform supports the PERST# signal, it should be
> toggled as per the requirements in the electromechanical specifications like
> PCIe CEM, Mini, and M.2. Since the pwrctrl framework is controlling the power
> supplies, it should also toggle PERST# as per the requirements in the above
> mentioned specifications. Right now, it is just controlling the power to the
> components and rely on controller drivers to toggle PERST#, which goes against
> the specs. For instance, controller drivers will deassert PERST# even before the
> pwrctrl driver enables the supplies. This causes the device to see PERST#
> deassert immediately after power on, thereby violating the delay requirements in
> the PCI Electromechanical specs.
>
> [...]

Applied, thanks!

[2/4] PCI: qcom: Move host bridge 'phy' and 'reset' pointers to struct qcom_pcie_port
commit: af8df709bf365f5583d31091280354e1ef0b201f

Best regards,
--
Manivannan Sadhasivam <mani@xxxxxxxxxx>