Re: [PATCH] mmc: sdhci-brcmstb: Add ARCH_BCM2835 option

[Andrea della Porta <andrea.porta@suse.com>]

Hi Peter,

On 13:22 Thu 20 Jun     , Peter Robinson wrote:
> Hi Andrea,
> 
> > On 08:42 Thu 20 Jun     , Peter Robinson wrote:
> > > The Raspberry Pi devices have to date all used ARCH_BCM2835
> > > as their SoC arch dependency so configurations that use this
> > > and not BRCMSTB won't end up with this module in their config.
> >
> > AFAIK the BCM2712 (RPi5) is the only SoC of the Raspberry family
> > that has an MMC host controller that is more or less like the one
> > present on the STB line silicon. Adding ARCH_BCM2835 to the dependency
> > will then allow RPi<=4 to use this driver for which they do not
> > have the relevant hw.
> 
> It won't use the driver due to the different compatibles, it just
> allows the driver to be available. The various different gens of RPi
> now have around 4 different types of MMC controller in use.

True, so why make a driver available if I can't use it anyway? No other
SoC served by ARCH_BCM2835 have that hw, but as you said, every one of them 
have different controllers best served by anything else but SDHCI_BRCMSTB.

Thanks,
Andrea

> 
> > If I'm correct about the aforementioned point, I'd be inclined to
> > avoid this change, then.
> >
> > Many thanks,
> > Andrea
> >
> > >
> > > Cc: Andrea della Porta <andrea.porta@suse.com>
> > > Cc: Stefan Wahren <wahrenst@gmx.net>
> > > Cc: Adrian Hunter <adrian.hunter@intel.com>
> > > Cc: Ulf Hansson <ulf.hansson@linaro.org>
> > > Fixes: 40f22df5269e6 ("mmc: sdhci-brcmstb: Add BCM2712 support")
> > > Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
> > > ---
> > >  drivers/mmc/host/Kconfig | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> > > index bb0d4fb0892ae..eb3ecfe055910 100644
> > > --- a/drivers/mmc/host/Kconfig
> > > +++ b/drivers/mmc/host/Kconfig
> > > @@ -1016,7 +1016,7 @@ config MMC_SDHCI_MICROCHIP_PIC32
> > >
> > >  config MMC_SDHCI_BRCMSTB
> > >       tristate "Broadcom SDIO/SD/MMC support"
> > > -     depends on ARCH_BRCMSTB || BMIPS_GENERIC || COMPILE_TEST
> > > +     depends on ARCH_BRCMSTB || ARCH_BCM2835 || BMIPS_GENERIC || COMPILE_TEST
> > >       depends on MMC_SDHCI_PLTFM
> > >       select MMC_CQHCI
> > >       default ARCH_BRCMSTB || BMIPS_GENERIC
> > > --
> > > 2.45.2
> > >