[Intel-gfx] [PATCH 2/4] drm/i915/selftests: align more to real device lifetimes

[Daniel Vetter]

On Fri, Sep 18, 2020 at 7:50 PM Matthew Auld
<matthew.william.auld at gmail.com> wrote:
>
> On Fri, 18 Sep 2020 at 14:25, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> >
> > The big change is device_add so that device_del can auto-cleanup
> > devres resources. This allows us to use devm_drm_dev_alloc, which
> > removes the last user of drm_dev_init.
> >
> > v2: Rebased
> >
> > v3: use devres_open/release_group so we can use devm without real
> > hacks in the driver core or having to create an entire fake bus for
> > testing drivers. Might want to extract this into helpers eventually,
> > maybe as a mock_drm_dev_alloc or test_drm_dev_alloc.
> >
> > v4:
> > - Fix IS_ERR handling (Matt)
> > - Delete surplus put_device() in mock_device_release (intel-gfx-ci)
> >
> > Cc: Matthew Auld <matthew.william.auld at gmail.com>
> > Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com> (v3)
> > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > ---
> >  .../gpu/drm/i915/selftests/mock_gem_device.c  | 44 +++++++++++--------
> >  1 file changed, 25 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
> > index ac600d395c8f..816f9af15fb3 100644
> > --- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
> > +++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
> > @@ -79,8 +79,6 @@ static void mock_device_release(struct drm_device *dev)
> >
> >  out:
> >         i915_params_free(&i915->params);
> > -       put_device(&i915->drm.pdev->dev);
> > -       i915->drm.pdev = NULL;
> >  }
> >
> >  static struct drm_driver mock_driver = {
> > @@ -128,12 +126,6 @@ struct drm_i915_private *mock_gem_device(void)
> >         pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
> >         if (!pdev)
> >                 return NULL;
> > -       i915 = kzalloc(sizeof(*i915), GFP_KERNEL);
> > -       if (!i915) {
> > -               kfree(pdev);
> > -               return NULL;
> > -       }
> > -
> >         device_initialize(&pdev->dev);
> >         pdev->class = PCI_BASE_CLASS_DISPLAY << 16;
> >         pdev->dev.release = release_dev;
> > @@ -144,8 +136,29 @@ struct drm_i915_private *mock_gem_device(void)
> >         /* HACK to disable iommu for the fake device; force identity mapping */
> >         pdev->dev.iommu = &fake_iommu;
> >  #endif
> > +       err = device_add(&pdev->dev);
> > +       if (err) {
> > +               kfree(pdev);
> > +               return NULL;
> > +       }
> > +
> > +       if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
> > +               device_del(&pdev->dev);
> > +               return NULL;
> > +       }
> > +
> > +       i915 = devm_drm_dev_alloc(&pdev->dev, &mock_driver,
> > +                                 struct drm_i915_private, drm);
> > +       if (IS_ERR(i915)) {
> > +               pr_err("Failed to allocate mock GEM device: err=%d\n", err);
>
> err = PTR_ERR(i915)

Are you sure? We return a pointer here, and callers just expect NULL
when stuff fails (so neither errno nor ptr-encoded errno).
-Daniel

> Reviewed-by: Matthew Auld <matthew.auld at intel.com>



-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch