Re: [PATCH RESEND 0/7] Introduce MEDIA_VERSION to end KENREL_VERSION abuse in media
From: Stephen Hemminger
Date: Thu Jun 29 2017 - 13:01:27 EST
On Thu, 29 Jun 2017 11:42:59 +0200
Johannes Thumshirn <jthumshirn@xxxxxxx> wrote:
> On Sat, Jun 24, 2017 at 05:15:07PM -0300, Mauro Carvalho Chehab wrote:
> > Sorry, but I can't see any advantage on it. On the downside, it
> > includes the media controller header file (media.h) where it
> > is not needed.
>
> My reasoning was the differences in semantics. KERNEL_VERSION() is for
> encoding the kernel's version triplet not a API or Hardware or whatever
> version. Other subsystems do this as well, for instance in NVMe we have the
> NVME_VS() macro which is used to encode the NVMe Spec compliance from a human
> readable form to the hardware's u32. Also KERNEL_VERISON() shouldn't have
> in-tree users IMHO. Yes there is _one_ other user of it in-tree which is EXT4
> and I already talked to Jan Kara about it and we decided to leave it in until
> 4.20.
>
> Byte,
> Johannes
If you read Linus's comments on version.
Driver version is meaningless and there is a desire to rip it out of all
drivers. The reason is that drivers must always behave the same, i.e you
can't use version to change API/ABI behavior.
Any upstream driver should never use KERNEL_VERSION().