[PATCH v5 2/2] mailbox: mediatek: Add mtk-vcp-mailbox driver

[Jassi Brar]

On Tue, Sep 23, 2025 at 1:46 AM Jjian Zhou (周建) <Jjian.Zhou at mediatek.com> wrote:
>
> On Thu, 2025-09-18 at 18:50 -0500, Jassi Brar wrote:
> > External email : Please do not click links or open attachments until
> > you have verified the sender or the content.
> >
> >
> > On Thu, Aug 21, 2025 at 9:12 PM Jjian Zhou <jjian.zhou at mediatek.com>
> > wrote:
> >
> > .....
> >
> > > +#include <linux/module.h>
> > > +#include <linux/of.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/slab.h>
> > > +
> > > +struct mtk_vcp_mbox_priv {
> >
> > Maybe 'mtk_vcp_mbox' is a more appropriate name ?
> >
> > > +       void __iomem *base;
> > > +       struct device *dev;
> > > +       struct mbox_controller mbox;
> > > +       const struct mtk_vcp_mbox_cfg *cfg;
> > > +       struct mtk_ipi_info ipi_recv;
> >
> > Maybe also have "struct mbox_chan chan[1]; " so that you don't have
> > to
> > allocate one during the probe.
> > Also if you have  "struct mbox_controller mbox;" as the first member,
> > you could simply typecast that to get this structure.
> > Something like "struct mpfs_mbox" in mailbox-mpfs.c
> >
>
>
> ERROR:FLEXIBLE_ARRAY: Use C99 flexible arrays - see
> https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays
> #81: FILE: drivers/mailbox/mtk-vcp-mailbox.c:24:
> +       struct mbox_chan chans[1];
> +};
>
> Can we ignore this error?
>
It seems single element style is deprecated. While we know what we are
doing, let us placate that error by
       struct mbox_chan mch;
       struct mbox_chan chans[];
and set  chans = &mch