Re: [PATCH v2] power: sequencing: qcom-wcn: power off WLAN at probe

[sashiko-bot@kernel.org]

> The WLAN enable GPIO is requested with GPIOD_ASIS and then kept at its
> current level, so that a WLAN module left powered on by the firmware is
> not switched off. The FIXME explains why: toggling it would take the
> PCIe link down, and the controller driver could not recover from that.
> 
> That reasoning held while the PCIe link was trained before the
> sequencer probed. Since commit b921aa3f8dec ("PCI/pwrctrl: Switch to
> pwrctrl create, power on/off, destroy APIs"), qcom_pcie_host_init()
> powers the endpoint through pwrctrl before it starts link training, and
> defers until the pwrctrl driver is bound. That driver cannot bind
> before this sequencer has probed. Power-on therefore always comes
> before link training, and keeping the firmware state is now harmful.
> 
> On the Microsoft Surface Pro 11 (X1E80100), the WCN7850 sits on a
> PCIe port without a PERST# GPIO. While pci-pwrctrl-pwrseq is not yet
> [ ... ]
> Fixes: b921aa3f8dec ("PCI/pwrctrl: Switch to pwrctrl create, power on/off, destroy APIs")
> Closes: https://lore.kernel.org/all/CAPjyS8dY0Q_o3XmFjuKZZsjhzhoSNL+ZGJtw5cQt8HiV3sUtxA@mail.gmail.com/
> Cc: stable@vger.kernel.org
> Assisted-by: LLM
> Signed-off-by: François Roux <franzelfranzel@gmail.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261004165124.4277-1-franzelfranzel@gmail.com?part=1