diff --git a/drivers/staging/dgnc/dgnc_cls.c b/drivers/staging/dgnc/dgnc_cls.c
index 28a3e1676f070441624a43006745687bae5644a3..3112c25282a7b88d33a0434e21410ac40be0ba89 100644
--- a/drivers/staging/dgnc/dgnc_cls.c
+++ b/drivers/staging/dgnc/dgnc_cls.c
@@ -609,7 +609,9 @@ static void cls_flush_uart_write(struct channel_t *ch)
 
 	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT),
 	       &ch->ch_cls_uart->isr_fcr);
-	usleep_range(10, 20);
+
+	/* Must use *delay family functions in atomic context */
+	udelay(10);
 
 	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 }