[PATCH v5 3/5] docs: staging: gpio-rpmsg: gpio over rpmsg bus

[Shenwei Wang]

> -----Original Message-----
> From: Andrew Lunn <andrew at lunn.ch>
> Sent: Wednesday, November 12, 2025 7:42 AM
> To: Shenwei Wang <shenwei.wang at nxp.com>
> Cc: Linus Walleij <linus.walleij at linaro.org>; Bjorn Andersson
> <andersson at kernel.org>; Mathieu Poirier <mathieu.poirier at linaro.org>; Rob
> Herring <robh at kernel.org>; Krzysztof Kozlowski <krzk+dt at kernel.org>; Conor
> Dooley <conor+dt at kernel.org>; Shawn Guo <shawnguo at kernel.org>; Sascha
> Hauer <s.hauer at pengutronix.de>; Jonathan Corbet <corbet at lwn.net>; Bartosz
> Golaszewski <brgl at bgdev.pl>; Pengutronix Kernel Team
> <kernel at pengutronix.de>; Fabio Estevam <festevam at gmail.com>; Peng Fan
> <peng.fan at nxp.com>; linux-remoteproc at vger.kernel.org;
> devicetree at vger.kernel.org; imx at lists.linux.dev; linux-arm-
> kernel at lists.infradead.org; linux-kernel at vger.kernel.org; linux-
> doc at vger.kernel.org; dl-linux-imx <linux-imx at nxp.com>
> Subject: [EXT] Re: [PATCH v5 3/5] docs: staging: gpio-rpmsg: gpio over rpmsg bus
> 
> Since this has not been merged yet, there are no existing systems.
> 

In this context, "system" refers to both Linux and the remote firmware. The remote firmware 
for i.MX platforms has already been released and widely used by our customers. Maintaining 
compatibility with the existing firmware would provide a better solution for customers.

Thanks,
Shenwei

> It is well known that what gets merged into mainline is often different to the
> initial out of tree version. You just need to deal with it. One option you have is to
> set the vendor byte to 1, so indicating NXP. If Linux uses vendor 0, it might be
> your out of tree vendor driver, not the in kernel driver. Just document in the
> specification vendor 0 is reserved.
> 
> You are going to have to modify your firmware anyway, level interrupts are
> broken. And this is an example of why quirks are needed.
> 
>         Andrew