[Backport of upstream commit f6ff4f67cdf8455d0a4226eeeaf5af17c37d05eb, with
an additional NULL pointer guard that is required for kernels 3.17 and older.
To be precise, any kernel that does *not* have commit 954605ca3 "drm/radeon:
use common fence implementation for fences, v4" requires this additional
NULL pointer guard.]
An arbitrary amount of time can pass between spin_unlock and
radeon_fence_wait_any, so we need to ensure that nobody frees the
fences from under us.
Based on the analogous fix for amdgpu.
Signed-off-by: Nicolai H?hnle <nicolai.haehnle@amd.com>
Reviewed-by: Christian K?nig <christian.koenig@amd.com> (v1 + fix)
Tested-by: Lutz Euler <lutz.euler@freenet.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Nicolai Hähnle
f839050dd4