RE: [patch v1] drivers/platform/x86: introduce support for Mellanox hotplug driver

[Vadim Pasternak]

> -----Original Message-----
> From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
> Sent: Thursday, September 22, 2016 4:53 PM
> To: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> Cc: dvhart@xxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; geert@xxxxxxxxxxxxxx;
> akpm@xxxxxxxxxxxxxxxxxxxx; kvalo@xxxxxxxxxxxxxx; mchehab@xxxxxxxxxx;
> linux@xxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; platform-driver-
> x86@xxxxxxxxxxxxxxx; jiri@xxxxxxxxxxx
> Subject: Re: [patch v1] drivers/platform/x86: introduce support for Mellanox
> hotplug driver
> 
> On Thu, Sep 22, 2016 at 01:50:28PM +0000, Vadim Pasternak wrote:
> >
> >
> > > -----Original Message-----
> > > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
> > > Sent: Thursday, September 22, 2016 4:43 PM
> > > To: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> > > Cc: dvhart@xxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; geert@xxxxxxxxxxxxxx;
> > > akpm@xxxxxxxxxxxxxxxxxxxx; kvalo@xxxxxxxxxxxxxx; mchehab@xxxxxxxxxx;
> > > linux@xxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; platform-driver-
> > > x86@xxxxxxxxxxxxxxx; jiri@xxxxxxxxxxx
> > > Subject: Re: [patch v1] drivers/platform/x86: introduce support for
> > > Mellanox hotplug driver
> > >
> > > On Thu, Sep 22, 2016 at 01:01:46PM +0000, Vadim Pasternak wrote:
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
> > > > > Sent: Thursday, September 22, 2016 3:31 PM
> > > > > To: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> > > > > Cc: dvhart@xxxxxxxxxxxxx; davem@xxxxxxxxxxxxx;
> > > > > geert@xxxxxxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx;
> > > > > kvalo@xxxxxxxxxxxxxx; mchehab@xxxxxxxxxx; linux@xxxxxxxxxxxx;
> > > > > linux-kernel@xxxxxxxxxxxxxxx; platform-driver-
> > > > > x86@xxxxxxxxxxxxxxx; jiri@xxxxxxxxxxx
> > > > > Subject: Re: [patch v1] drivers/platform/x86: introduce support
> > > > > for Mellanox hotplug driver
> > > > >
> > > > > On Thu, Sep 22, 2016 at 01:14:27PM +0000, vadimp@xxxxxxxxxxxx
> wrote:
> > > > > > From: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> > > > > >
> > > > > > Enable system support for the Mellanox Technologies hotplug
> > > > > > platform driver, which provides support for the next Mellanox
> > > > > > basic
> > > systems:
> > > > > > "msx6710", "msx6720", "msb7700", "msn2700", "msx1410",
> > > > > > "msn2410", "msb7800", "msn2740", "msn2100" and also various
> > > > > > number of derivative systems from the above basic types.
> > > > > > This driver handles hot-plug events for the power suppliers,
> > > > > > power cables and fans for the above systems.
> > > > > >
> > > > > > The Kconfig currently controlling compilation of this code is:
> > > > > > driver/platform/x86:config MLX_CPLD_PLATFORM
> > > > > >                        tristate "Mellanox platform hotplug driver support"
> > > > > >
> > > > > > Signed-off-by: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> > > > > > ---
> > > > > >  MAINTAINERS                                   |   7 +
> > > > > >  drivers/platform/x86/Kconfig                  |  10 +
> > > > > >  drivers/platform/x86/Makefile                 |   1 +
> > > > > >  drivers/platform/x86/mlxcpld-hotplug.c        | 543
> > > > > ++++++++++++++++++++++++++
> > > > > >  include/linux/platform_data/mlxcpld-hotplug.h |  90 +++++
> > > > >
> > > > > Why do you need a platform_data .h file for a stand-alone driver?
> > > > >
> > > >
> > > > I have another module mlx-platform, which is reviewed now (I also
> > > > got a number feedbacks from you on this matter).  I want to
> > > > activate mlxcpld-hotplug from this module.
> > >
> > > Ah.  Hm, I thought "platform_data" was depreciated.  Really, there
> > > is no way to put this in acpi or device tree?  This feels so 1990's...
> > >
> >
> > I can't put in ACPI, since we don't have it.
> > Regarding device tree - I know how to do it for ARM and PPC, but I didn't find
> some good examples for x86.
> > Maybe you can give me some reference for that?
> 
> I have no idea, sorry :(

I see several not so good " artificial" examples of device tree usage in x86.
And folder include/linux/platform_data/ contains about thousand files.