On Tue, Mar 01, 2022 at 02:30:00AM +0000, Linyu Yuan (QUIC) wrote: > > From: mka@xxxxxxxxxxxx <mka@xxxxxxxxxxxx> > > Sent: Tuesday, March 1, 2022 2:29 AM > > To: Linyu Yuan (QUIC) <quic_linyyuan@xxxxxxxxxxx> > > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; Tao Wang (Consultant) (QUIC) > > <quic_wat@xxxxxxxxxxx>; balbi@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > > dianders@xxxxxxxxxxxx; frowand.list@xxxxxxxxx; hadess@xxxxxxxxxx; > > krzk@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; > > mathias.nyman@xxxxxxxxx; michal.simek@xxxxxxxxxx; > > peter.chen@xxxxxxxxxx; ravisadineni@xxxxxxxxxxxx; robh+dt@xxxxxxxxxx; > > rogerq@xxxxxxxxxx; stern@xxxxxxxxxxxxxxxxxxx; swboyd@xxxxxxxxxxxx > > 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 ? Add the VID:PID and compatible strings to onboard_usb_hub.c, analogous to those for the RTS5411 and RTS5414. More work will be needed if the hub needs a special power up or power down sequence (multiple regulators, GPIOs, ...) > 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. Not really. I doubt that what you are suggesting would work. The easiest thing to convince people would probably be to send a patch (based on this one) with a working implementation of your idea.
