staging: dgnc: replace usleep_range with udelay

udelay is impelmented using a busy-wait loop and consumes CPU cycles while usleep_range is implemented using interrupts. cls_flush_uart_write() is called after a channel lock is acquired i.e. an atomic context. Hence delay in this method should use udelay instead of usleep_range.

---
Change in v2:
- Edit commit message to explain why udelay should be used

 drivers/staging/dgnc/dgnc_cls.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 28a3e16..7068c3b 100644
@@ -609,7 +609,7 @@ 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);
+	udelay(10);
 
 	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 }

2.7.4

No, put a comment in the code above the line itself about this.

thanks,

greg k-h