Messages in this thread | | | From | "Linyu Yuan (QUIC)" <> | Subject | RE: 回复: 回复: Re: [PATCH v20 3/5] usb: misc: Add onboard usb hub driver | Date | Tue, 1 Mar 2022 02:30:00 +0000 |
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> From: mka@chromium.org <mka@chromium.org> > Sent: Tuesday, March 1, 2022 2:29 AM > To: Linyu Yuan (QUIC) <quic_linyyuan@quicinc.com> > Cc: gregkh@linuxfoundation.org; Tao Wang (Consultant) (QUIC) > <quic_wat@quicinc.com>; balbi@kernel.org; devicetree@vger.kernel.org; > dianders@chromium.org; frowand.list@gmail.com; hadess@hadess.net; > krzk@kernel.org; linux-kernel@vger.kernel.org; linux-usb@vger.kernel.org; > mathias.nyman@intel.com; michal.simek@xilinx.com; > peter.chen@kernel.org; ravisadineni@chromium.org; robh+dt@kernel.org; > rogerq@kernel.org; stern@rowland.harvard.edu; swboyd@chromium.org > Subject: Re: 回复: 回复: Re: [PATCH v20 3/5] usb: misc: Add > onboard_usb_hub driver > > > > > Hi Greg and mka, > > > > Let's make it clear that we are talking about once this driver is approved > into usb tree, > > If we use different USB HUB which have VID/PID not defined in this driver, > > We need to update this driver. > > > > But if we defined VID/PID in device tree(for a specific board, manufacture > should know VID/PID from HUB it used), > > dynamic parsed by the driver, then we don't need to change this driver > (increase VID/PID table). > > As per my earlier reply, the kernel/USB core uses the VID:PID reported > by the USB device, the compatible string in the device tree is purely > informational. That's not something that could be changed by this > driver. I can't fully understand this comment, could you please share step if we want to add a new HUB support, what should we do ? nothing ?
If do nothing, can we remove id_table from onboard_hub_usbdev_driver ? > > And even if the VID:PID from the device tree was used: how is the > kernel supposed to know that the onboard_hub driver should be > probed for a given VID:PID from the device tree, without listing > the VID:PID (or compatible string) in the driver (which is what > you seem to seek to avoid)? In my opinion, if it need update VID/PID table in this driver to support a new HUB, we can parse VID/PID from device tree and create dynamic VID/PID entry to id_table of onboard_hub_usbdev_driver.
Hope you can understand what I said.
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