The patch titled
Uartlite: speed up console output
has been added to the -mm tree. Its filename is
uartlite-speed-up-console-output.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Uartlite: speed up console output
From: Grant Likely <grant.likely@xxxxxxxxxxxx>
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 <grant.likely@xxxxxxxxxxxx>
Cc: Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/serial/uartlite.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff -puN drivers/serial/uartlite.c~uartlite-speed-up-console-output drivers/serial/uartlite.c
--- a/drivers/serial/uartlite.c~uartlite-speed-up-console-output
+++ a/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();
}
}
_
Patches currently in -mm which might be from grant.likely@xxxxxxxxxxxx are
uartlite-speed-up-console-output.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
