[PATCH 4.15 011/146] drm/i915: Fix rsvd2 mask when out-fence is returned

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>

commit b1b13780ab06ef8c770dd9cbe31dac549a11630e upstream.

GENMASK_ULL wants the high bit of the mask first. The current value
cancels the in-fence when an out-fence is returned.

Fixes: fec0445caa273 ("drm/i915: Support explicit fencing for execbuf")
Testcase: igt/gem_exec_fence/keep-in-fence*
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20180214191827.8465-1-daniele.ceraolospurio@xxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # v4.12+
(cherry picked from commit b6a88e4a804cf5a71159906e16df2c1fc7196f92)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -2419,7 +2419,7 @@ err_request:
 	if (out_fence) {
 		if (err == 0) {
 			fd_install(out_fence_fd, out_fence->file);
-			args->rsvd2 &= GENMASK_ULL(0, 31); /* keep in-fence */
+			args->rsvd2 &= GENMASK_ULL(31, 0); /* keep in-fence */
 			args->rsvd2 |= (u64)out_fence_fd << 32;
 			out_fence_fd = -1;
 		} else {