intel_sst: ignore IRQ when suspended

The irq for audio is shared, so when device is supended driver should
not the read register and ignore the interrupt.

This patch ignores interrupts when device is suspended.
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Ramesh Babu K V <ramesh.babu@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/intel_sst/intel_sst.c

@@ -107,6 +107,9 @@ static irqreturn_t intel_sst_interrupt(int irq, void *context)
 	unsigned int size = 0, str_id;
 	struct stream_info *stream ;
 
+	/* Do not handle interrupt in suspended state */
+	if (drv->sst_state == SST_SUSPENDED)
+		return IRQ_NONE;
 	/* Interrupt arrived, check src */
 	isr.full = sst_shim_read(drv->shim, SST_ISRX);