Re: [PATCH 2/2] TVP514x V4L int device driver support

[David Brownell <david-b@pacbell.net>]

On Sunday 23 November 2008, Trilok Soni wrote:
> > 2) Please use the media/v4l2-i2c-drv.h or media/v4l2-i2c-drv-legacy.h
> > header to hide some of the i2c complexity (again, see e.g. saa7115.c).
> > The i2c API tends to change a lot (and some changes are upcoming) so

What "changes" do you mean?  Since this is not a legacy-style
driver (yay!), the upcoming changes won't affect it at all.


> > using this header will mean that i2c driver changes will be minimal in
> > the future. In addition it will ensure that this driver can be compiled
> > with older kernels as well once it is part of the v4l-dvb repository.
> 
> I don't agree with having support to compile with older kernels.

Right.  Folk wanting legacy tvp5146 and tvp5140 support could
try to use the legacy drivers from the DaVinci tree.


> Even though I2C APIs change as lot it is for good, and creating
> abstractions doesn't help as saa7xxx is family of chips where I don't
> see the case here. Once this driver is mainlined if someone does i2c
> subsystem change which breaks this driver from building then he/she
> has to make changes to all the code affecting it.

And AFAIK no such change is anticipated.  The conversion from
legacy style I2C drivers to "new style" driver-model friendly
drivers is progressing fairly well, so that legacy support can
be completely removed.


> I am not in favour of adding support to compile with older kernels.

My two cents:  I'm not in favor either.  In fact that's the
general policy for mainline drivers, and I'm surprised to hear
any maintainer suggest it be added.

- Dave