From 1d6b698764084510fe6168bb5b650165dced03ae Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Tue, 23 Oct 2007 14:27:46 +1000 Subject: [PATCH] [POWERPC] Uartlite: speed up console output Change the wait_tx routine to call cpu_relax() instead of udelay() to reduce console output latency and test for the TXFULL bit instead of TXEMPTY. That way the FIFO doesn't need to by 100% flushed before writing the next character. Signed-off-by: Grant Likely Acked-by: Peter Korsgaard Signed-off-by: Josh Boyer --- drivers/serial/uartlite.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/serial/uartlite.c b/drivers/serial/uartlite.c index dfef83f14960..a85f2d31a686 100644 --- a/drivers/serial/uartlite.c +++ b/drivers/serial/uartlite.c @@ -329,12 +329,14 @@ static struct uart_ops ulite_ops = { static void ulite_console_wait_tx(struct uart_port *port) { int i; + u8 val; - /* wait up to 10ms for the character(s) to be sent */ - for (i = 0; i < 10000; i++) { - if (readb(port->membase + ULITE_STATUS) & ULITE_STATUS_TXEMPTY) + /* Spin waiting for TX fifo to have space available */ + for (i = 0; i < 100000; i++) { + val = readb(port->membase + ULITE_STATUS); + if ((val & ULITE_STATUS_TXFULL) == 0) break; - udelay(1); + cpu_relax(); } }