On Tue, 13 Feb 2024 at 15:50, Dmitry Baryshkov
<dmitry.baryshkov@xxxxxxxxxx> wrote:
>
> On Mon, 12 Feb 2024 at 23:55, Rob Clark <robdclark@xxxxxxxxx> wrote:
> >
> > From: Rob Clark <robdclark@xxxxxxxxxxxx>
> >
> > DRM_MODESET_LOCK_ALL_BEGIN() has a hidden trap-door (aka retry loop),
> > which means we can't rely too much on variable initializers.
> >
> > Fixes: 6e455f5dcdd1 ("drm/crtc: fix uninitialized variable use")
> > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> > ---
> > I have mixed feelings about DRM_MODESET_LOCK_ALL_BEGIN() (and friends)
> > magic. On one hand it simplifies the deadlock/back dance. OTOH it
> > conceals a nasty sharp edge. Maybe it is better to have the complicated
> > restart path a bit more explicit, like it was originally.
> >
> > drivers/gpu/drm/drm_crtc.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > index cb90e70d85e8..65f9f66933bb 100644
> > --- a/drivers/gpu/drm/drm_crtc.c
> > +++ b/drivers/gpu/drm/drm_crtc.c
> > @@ -904,6 +904,7 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
> > connector_set = NULL;
> > fb = NULL;
> > mode = NULL;
> > + num_connectors = 0;
>
> Nit: I think we should move all this next to the
> DRM_MODESET_LOCK_ALL_BEGIN() and drop initialisation from the prologue
> of the function, but it's definitely a separate and more intrusive
> story.
>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
After running this through CI:
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> #sc7180, sdm845
> > DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);
>
>
> --
> With best wishes
> Dmitry
--
With best wishes
Dmitry
