[igt-dev] [PATCH i-g-t] lib: Rework __kms_addfb() function

[Arkadiusz Hiler]

On Wed, Apr 10, 2019 at 12:34:07PM +0100, Chris Wilson wrote:
> Quoting Arkadiusz Hiler (2019-04-10 12:28:08)
> > On Wed, Apr 03, 2019 at 07:24:39PM -0300, Rodrigo Siqueira wrote:
> > > The function __kms_addfb() and drmModeAddFB2WithModifiers() have a
> > > similar code. Due to this similarity, this commit replace part of the
> > > code inside __kms_addfb() by using drmModeAddFB2WithModifiers().
> > 
> > igt master % grep '^libdrm_version' meson.build
> > libdrm_version = '>=2.4.82'
> 
> Why introduce a dependency? The primary purpose of igt is breaking
> ioctls, and that typically requires avoiding any protective libraries.
> In particular, we want to be very, very clear about what igt is doing
> (in terms of kernel api/abi) and not obfuscate.
> -Chris

We depend on one additional call from a library that we already use
widely across the whole codebase and it's straight up a simple wrapper.
Which seems to be a pattern - we us those simple wrapper where
available, and write our own if there is nothing suitable.

It's ok to have some tests that poke the IOCTL more directly, like we
kms_addfb_basic for ADDFB2 (which still uses drmIoctl, so where do we
draw a line?).

If any of thoe wrappers goes awry we can just drop-in replace it with
the original, simple version anyway.

-- 
Cheers,
Arek