Re: [PATCH 1/2] misc: rtsx: Move Realtek Card Reader Driver to misc

[Lee Jones <lee.jones@linaro.org>]

On Thu, 19 Oct 2017, Arnd Bergmann wrote:

> On Thu, Oct 19, 2017 at 5:22 AM,  <rui_feng@realsil.com.cn> wrote:
> > From: Rui Feng <rui_feng@realsil.com.cn>
> >
> > Because Realtek PCIE card reader driver is a pcie driver,
> > and it bridges mmc subsystem and memstick subsystem, it's
> > not a mfd driver. Greg and Lee Jones had a discussion about
> > where to put the driver, the result is that misc is a good
> > place for it, so I move all files to misc. If I don't move
> > it to a right place, I can't add any patch for this driver.
> >
> > Signed-off-by: Rui Feng <rui_feng@realsil.com.cn>
> > ---
> >  drivers/memstick/host/rtsx_pci_ms.c      |  2 +-
> >  drivers/mfd/Kconfig                      | 11 -----------
> >  drivers/mfd/Makefile                     |  2 --
> >  drivers/misc/Kconfig                     |  1 +
> >  drivers/misc/Makefile                    |  1 +
> >  drivers/misc/realtek/Kconfig             | 10 ++++++++++
> >  drivers/misc/realtek/Makefile            |  3 +++
> >  drivers/{mfd => misc/realtek}/rtl8411.c  |  1 -
> >  drivers/{mfd => misc/realtek}/rts5209.c  |  1 -
> >  drivers/{mfd => misc/realtek}/rts5227.c  |  1 -
> 
> Thanks for redoing the patch. If Lee and Greg want to see it moved
> here, I won't object, but I'd still like to understand the distinction better,
> since there are likely going to be other drivers in the same situation
> (either adding into misc or mfd) and it would be good if we can all
> give consistent advice.
> 
> Greg, Lee: can you come up with a simple definition of what an
> MFD is that this driver does not fit into? What about other
> PCI drivers like intel-lpss-pci and lpc_ich? Are they different
> from this one or should they also be moved out of MFD?

MFDs drivers don't *do* anything.  They handle shared resources,
register featureful devices residing in other subsystems and provide
simple shared functionality pertaining to the chip as a whole.

These card reader devices *are* the featureful drivers and brim with
useful functionality.

intel-lpss-pci and lpc_ich conform to the aforementioned definition.
 
-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog