accel/ivpu: Do not trigger extra VPU reset if the VPU is idle

commit 9f7e361 upstream.

Turning off the PLL and entering D0i3 will reset the VPU so
an explicit IP reset is redundant.
But if the VPU is active, it may interfere with PLL disabling
and to avoid that, we have to issue an additional IP reset
to silence the VPU before turning off the PLL.

Fixes: a8fed6d ("accel/ivpu: Fix power down sequence")
Cc: stable@vger.kernel.org # 6.3.x
Signed-off-by: Andrzej Kacprowski <andrzej.kacprowski@linux.intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230525103818.877590-1-stanislaw.gruszka@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/accel/ivpu/ivpu_hw_mtl.c

@@ -754,18 +754,19 @@ static int ivpu_hw_mtl_power_down(struct ivpu_device *vdev)
 {
 	int ret = 0;
 
-	if (ivpu_hw_mtl_reset(vdev)) {
+	if (!ivpu_hw_mtl_is_idle(vdev) && ivpu_hw_mtl_reset(vdev)) {
 		ivpu_err(vdev, "Failed to reset the VPU\n");
-		ret = -EIO;
 	}
 
 	if (ivpu_pll_disable(vdev)) {
 		ivpu_err(vdev, "Failed to disable PLL\n");
 		ret = -EIO;
 	}
 
-	if (ivpu_hw_mtl_d0i3_enable(vdev))
-		ivpu_warn(vdev, "Failed to enable D0I3\n");
+	if (ivpu_hw_mtl_d0i3_enable(vdev)) {
+		ivpu_err(vdev, "Failed to enter D0I3\n");
+		ret = -EIO;
+	}
 
 	return ret;
 }