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To:     Matthias Kaehlcke <mka@chromium.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        Rob Herring <robh+dt@kernel.org>,
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        Mathias Nyman <mathias.nyman@intel.com>,
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Cc:     devicetree@vger.kernel.org, Peter Chen <peter.chen@kernel.org>,
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        Bastien Nocera <hadess@hadess.net>,
        Ravi Chandra Sadineni <ravisadineni@chromium.org>,
        Michal Simek <michal.simek@xilinx.com>,
        Douglas Anderson <dianders@chromium.org>,
        Roger Quadros <rogerq@kernel.org>,
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        Stephen Boyd <swboyd@chromium.org>,
        Dmitry Osipenko <digetx@gmail.com>,
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References: <20210813195228.2003500-1-mka@chromium.org>
 <20210813125146.v16.6.I7a3a7d9d2126c34079b1cab87aa0b2ec3030f9b7@changeid>
From:   Mathias Nyman <mathias.nyman@linux.intel.com>
Subject: Re: [PATCH v16 6/7] usb: host: xhci-plat: Create platform device for
 onboard hubs in probe()
Message-ID: <dfac0025-b693-2431-04c8-1dba7ef32141@linux.intel.com>
Date:   Wed, 20 Oct 2021 16:05:37 +0300
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Hi

On 13.8.2021 22.52, Matthias Kaehlcke wrote:
> Call onboard_hub_create/destroy_pdevs() from  _probe()/_remove()
> to create/destroy platform devices for onboard USB hubs that may
> be connected to the root hub of the controller. These functions
> are a NOP unless CONFIG_USB_ONBOARD_HUB=y/m.
> 
> Also add a field to struct xhci_hcd to keep track of the onboard hub
> platform devices that are owned by the xHCI.
> 
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---

Haven't really looked at this series until now.

Is there any reason why the xhci platform driver was selected as 
the best place to create/remove these onboard hub devices?

This ties the onboard hubs to xhci, and won't work in case we have onboard
hubs connected to a ehci controllers.

If separate devices for controlling onboard hub power is the right solution then
how about creating the onboard hub device in usb_add_hcd() (hcd.c), and
store it in struct usb_hcd.

A bit like how the roothub device is created, or PHYs are tuned.

Thanks
Mathias