[igt-dev] ✗ Fi.CI.IGT: failure for tests/i915/gen_mmap: fix no-op loops

[Ser, Simon]

On Fri, 2019-05-31 at 12:41 +0100, Chris Wilson wrote:
> Quoting Ser, Simon (2019-05-31 12:36:26)
> > Hi Martin,
> > 
> > On Wed, 2019-05-08 at 09:54 +0000, Ser, Simon wrote:
> > > These failures happen because of:
> > > 
> > > (gem_mmap:5289) CRITICAL: Failed assertion: mmap_ioctl(fd, &arg) == -22
> > > (gem_mmap:5289) CRITICAL: error: -2 != -22
> > > 
> > > Is this a genuine driver bug? Is the driver supposed to fail with
> > > ENOENT or EINVAL?
> > 
> > The authors haven't replied, so could we file a bug for this? Discussed
> > with Arek, the correct sequence of actions would be:
> 
> Don't knowingly push a broken test purporting to fix one breakage. The
> test is wrong.

A test that fails is better than a test that silently does nothing. At
least we know it's broken.

> You have git and could have checked that ENOENT was the ABI we settled
> on in
> 
> commit bf79cb914dbfe848add8bb76cbb8ff89110d29ff
> Author: Chris Wilson <chris at chris-wilson.co.uk>
> Date:   Wed Aug 4 14:19:46 2010 +0100
> 
>     drm: Use ENOENT consistently for the error return for an unmatched handle.
> 
>     This is consistent with trying to access a filename that not exist
>     within a directory which is a good analogy here. The main reason for the
>     change is that it is easy to confuse the error code of EBADF as an
>     performing an ioctl on an invalid file descriptor (rather than an
>     unknown object).
> 
>     Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>     Signed-off-by: Dave Airlie <airlied at redhat.com>
> 
> after being told not to EBADF.

I have absolutely no idea how I could've find this 2010 commit. But,
thanks to your reply, at least I can write a fix now. Thanks!