drivers: mbox: imx_mu: handle all interrupts for a channel

Handle all interrupts for a channel before going to next
channel. Previous code did an if/else check, so if both
a data rx interrupt and a notification interrupt were pending
for a channel, only one would be handled in the ISR. The
ISR would have to fire again (probably would be still pending)
for the other interrupt to be processed. This could even
lead to starvation/delay if another data rx interrupt got
pended again.

Signed-off-by: Mike J. Chen <[email protected]>

Author: mjchen0

drivers/mbox/mbox_nxp_imx_mu.c

@@ -195,12 +195,14 @@ static void mu_isr(const struct device *dev)
 				data->cb[i_channel](dev, i_channel, data->user_data[i_channel],
 						    &msg);
 			}
-		} else if ((flags & gen_int_mask) == gen_int_mask) {
+		}
+		if ((flags & gen_int_mask) == gen_int_mask) {
 			MU_ClearStatusFlags(config->base, gen_int_mask);
 			if (data->cb[i_channel]) {
 				data->cb[i_channel](dev, i_channel, data->user_data[i_channel],
 						    NULL);
 			}
 		}
+
 	}
 }