Re: [PATCH v7 0/8] Add support for handling PCIe M.2 Key E connectors in devicetree

[Manivannan Sadhasivam]

[Resending as my previous reply got bounced]

On Mon, Apr 13, 2026 at 07:33:12PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Apr 13, 2026 at 03:54:59PM +0800, Chen-Yu Tsai wrote:
> > Hi,
> > 
> > On Thu, Mar 26, 2026 at 01:36:28PM +0530, Manivannan Sadhasivam wrote:
> > > Hi,
> > > 
> > > This series is the continuation of the series [1] that added the initial support
> > > for the PCIe M.2 connectors. This series extends it by adding support for Key E
> > > connectors. These connectors are used to connect the Wireless Connectivity
> > > devices such as WiFi, BT, NFC and GNSS devices to the host machine over
> > > interfaces such as PCIe/SDIO, USB/UART and NFC. This series adds support for
> > > connectors that expose PCIe interface for WiFi and UART interface for BT. Other
> > > interfaces are left for future improvements.
> > 
> > Thanks for working on this. I started playing with it now that it is in
> > -next. The PCIe part works fine. I'm looking into how to fit the pwrseq
> > 
> > A couple questions:
> > 
> > - Given that this connector actually represents two devices, how do I
> >   say I want the BT part to be a wakeup source, but not the WiFi part?
> >   Does wakeup-source even work at this point?
> > 
> 
> You can't use the DT property since the devices are not described in DT
> statically. But you can still use the per-device 'wakeup' sysfs knob to enable
> wakeup.
> 
> > - Are there plans to do the SDIO part?
> > 
> 
> No, not at the moment. Feel free to take it up if you have the hardware and
> motivation :)
> 
> > - The matching done in the M.2 connector driver for pwrseq_get() seems a
> >   bit naive. It simply checks if the remote device in the OF graph is
> >   the same as the requesting device.
> > 
> >   I think this would run into issues with USB hubs. If I have a USB hub
> >   and two M.2 connectors, with both connectors connected to the same
> >   hub, pwrseq_get() is going to always return only one of the instances.
> >   This is because the USB hub has one device node with multiple OF graph
> >   ports.
> > 
> 
> Yeah, this is a known limitation. I'm trying to improve this part now and have
> the WIP commits here: https://github.com/Mani-Sadhasivam/linux/tree/pwrseq-bt-en-fixes
> 
> Once the merge window closes, I'll submit these.
> 
> - Mani
> 
> -- 
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