ASoC: Intel: Skylake: Verify the status bit before handling interrupt

Like we have in legacy mode HDA driver, we need to check the
status bit and handle interrupt only when it is not zero or all
bits set.  We typically see the status as all 1's when controller
resumes from suspend, So add the check here as well and don't
handle for these cases.
Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/skylake/skl-sst-dsp.c

@@ -262,6 +262,11 @@ irqreturn_t skl_dsp_sst_interrupt(int irq, void *dev_id)
 	val = sst_dsp_shim_read_unlocked(ctx, SKL_ADSP_REG_ADSPIS);
 	ctx->intr_status = val;
 
+	if (val == 0xffffffff) {
+		spin_unlock(&ctx->spinlock);
+		return IRQ_NONE;
+	}
+
 	if (val & SKL_ADSPIS_IPC) {
 		skl_ipc_int_disable(ctx);
 		result = IRQ_WAKE_THREAD;