RE: [PATCH v8 2/2] omap hsmmc: adaptation of sdma descriptor autoloading feature

Shilimkar, Santosh
2010-05-07T04:52:30Z

> -----Original Message-----
> From: Chikkature Rajashekar, Madhusudhan
> Sent: Thursday, May 06, 2010 9:50 PM
> To: Shilimkar, Santosh; 'kishore kadiyala'
> Cc: S, Venkatraman; linux-omap@vger.kernel.org; linux-mmc@vger.kernel.org; linux-arm-
> kernel@lists.arm.linux.org.uk; 'Adrian Hunter'; Kadiyala, Kishore; 'Tony Lindgren'
> Subject: RE: [PATCH v8 2/2] omap hsmmc: adaptation of sdma descriptor autoloading feature
>
>
>
> > -----Original Message-----
> > From: Shilimkar, Santosh [mailto:santosh.shilimkar@ti.com]
> > Sent: Thursday, May 06, 2010 4:39 AM
> > To: kishore kadiyala
> > Cc: S, Venkatraman; linux-omap@vger.kernel.org; linux-mmc@vger.kernel.org;
> > linux-arm-kernel@lists.arm.linux.org.uk; Chikkature Rajashekar,
> > Madhusudhan; Adrian Hunter; Kadiyala, Kishore; Tony Lindgren
> > Subject: RE: [PATCH v8 2/2] omap hsmmc: adaptation of sdma descriptor
> > autoloading feature
> >
> > > -----Original Message-----
> > > From: kishore kadiyala [mailto:kishorek.kadiyala@gmail.com]
> > > Sent: Thursday, May 06, 2010 2:32 PM
> > > To: Shilimkar, Santosh
> > > Cc: S, Venkatraman; linux-omap@vger.kernel.org; linux-
> > mmc@vger.kernel.org; linux-arm-
> > > kernel@lists.arm.linux.org.uk; Chikkature Rajashekar, Madhusudhan;
> > Adrian Hunter; Kadiyala, Kishore;
> > > Tony Lindgren
> > > Subject: Re: [PATCH v8 2/2] omap hsmmc: adaptation of sdma descriptor
> > autoloading feature
> > >
> > > <<snip>>
> > >
> > > >> I am not clear about the method. The board files export the
> > > >> omap_mmc_platform_data.
> > > >> Does it imply that all board files have to change and export
> > > >> the capability so that it can be queried ?
> > > > No. You don't have to modify the board files. This would need
> > > > change in devices.c which common for all omap boards.
> > > >
> > > > I don't have a strong opinion on this point but just put forth an
> > > > alternate way to avoid such SOC specific check in drivers.
> > > > You can take call on this
> > >
> > > Agree. How about adding a flag in hsmmc.h & omap_mmc_platform_data,
> > > that would take care of SDMA & SDMA_DLAOD in the driver instead going
> > > with SOC check .
> >
> > Good idea Kishore.
> > Venkat,
> > Can you do what kishore is suggesting.
> >
> omap_mmc_platform_data is MMC specific platform data. Why add a SDMA
> specific feature capability into it? Even though you add it there, you will
> still need to have a cpu check before that can be set in a common code.
>

CPU checks are allowed to be in the platform files. That is where such
machine/SOC specific differentiation should be done and not in the device
drivers.
That way device drivers remains clean and portable.

I want to stop this thread here since neither the patch author nor the file
maintainer thinks that cpu checks in the device drivers is bad idea.

Please decide within yourself and move on.

Regards,
Santosh