Messages in this thread | | | Date | Tue, 29 Sep 2020 12:53:00 +0200 | From | Daniel Vetter <> | Subject | Re: [PATCH v2 4/4] drm/qxl: use qxl pin function |
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On Tue, Sep 29, 2020 at 11:51:15AM +0200, Gerd Hoffmann wrote: > Otherwise ttm throws a WARN because we try to pin without a reservation. > > Fixes: 9d36d4320462 ("drm/qxl: switch over to the new pin interface") > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> > --- > drivers/gpu/drm/qxl/qxl_object.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c > index d3635e3e3267..eb45267d51db 100644 > --- a/drivers/gpu/drm/qxl/qxl_object.c > +++ b/drivers/gpu/drm/qxl/qxl_object.c > @@ -145,7 +145,7 @@ int qxl_bo_create(struct qxl_device *qdev, > return r; > } > if (pinned) > - ttm_bo_pin(&bo->tbo); > + qxl_bo_pin(bo);
I think this is now after ttm_bo_init, and at that point the object is visible to lru users and everything. So I do think you need to grab locks here instead of just incrementing the pin count alone.
It's also I think a bit racy, since ttm_bo_init drops the lock, so someone might have snuck in and evicted the object already.
I think what you need is to call ttm_bo_init_reserved, then ttm_bo_pin, then ttm_bo_unreserve, all explicitly. -Daniel
> *bo_ptr = bo; > return 0; > } > -- > 2.27.0 >
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
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