[PATCH] x86: spi: Only use the fast SPI peripheral when support

[Simon Glass]

Hi Bin,

On Mon, 30 Mar 2020 at 03:42, Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Hi Simon,
>
> On Sun, Mar 29, 2020 at 4:58 AM Simon Glass <sjg at chromium.org> wrote:
> >
> > Hi Bin,
> >
> > On Thu, 26 Mar 2020 at 10:38, Bin Meng <bmeng.cn at gmail.com> wrote:
> > >
> > > Hi Simon,
> > >
> > > On Fri, Mar 27, 2020 at 12:20 AM Simon Glass <sjg at chromium.org> wrote:
> > > >
> > > > HI Bin,
> > > >
> > > > On Wed, 25 Mar 2020 at 01:25, Bin Meng <bmeng.cn at gmail.com> wrote:
> > > > >
> > > > > Hi Simon,
> > > > >
> > > > > On Tue, Mar 24, 2020 at 9:45 PM Simon Glass <sjg at chromium.org> wrote:
> > > > > >
> > > > > > At present we query the memory map on boards which don't support it. Fix
> > > > > > this by only doing it on Apollo Lake.
> > > > > >
> > > > >
> > > > > I wonder isn't this check already covered in mrccache_get_region() below:
> > > > >
> > > > > ret = dm_spi_get_mmap(dev, &map_base, &map_size, &offset);
> > > > > if (!ret) {
> > > > > entry->base = map_base;
> > > > > } else {
> > > > > ret = dev_read_u32_array(dev, "memory-map", reg, 2);
> > > > > if (ret)
> > > > > return log_msg_ret("Cannot find memory map\n", ret);
> > > > > entry->base = reg[0];
> > > > > }
> > > >
> > > > Yes it is, so long as dm_spi_get_mmap() returns an error, as it does
> > > > with my patch.
> > >
> > > So does ich_get_mmap_bus() returns 0 on chromebook_link?
> >
> > Well on link the SPI peripheral is not a PCI device but a child of the
> > PCH. It is possible to read the registers but at present this only
> > works once you have the mmio_base (i.e. the PCH device is probed).
> > This function needs to work before probing (since FSP-S access needs
> > to happen without probing PCI).
> >
> > I suspect it would be possible to read the PCH base without probing
> > it, but it does add quite a bit of special-case code. What do you
> > think?
>
> I've looked at this. So this function mrccache_get_region() is broken
> on Minnowmax too. The call to uclass_find_first_device() returns
> nothing because SPI flash is not probed hence no SF device is found.

OK, so add to the DT, or do something else?

Regards,
Simon