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From David.Daney@caviumnetworks.com Wed Oct 6 13:21:08 2010
From: David Daney <ddaney@caviumnetworks.com>
To: linux-serial@vger.kernel.org, gregkh@suse.de,
linux-kernel@vger.kernel.org
Cc: David Daney <ddaney@caviumnetworks.com>
Subject: serial: 8250: Don't delay after transmitter is ready.
Date: Tue, 5 Oct 2010 11:40:07 -0700
Message-Id: <1286304007-4715-1-git-send-email-ddaney@caviumnetworks.com>
The loop in wait_for_xmitr() is delaying one extra uS after the ready
condition has been met. Rewrite the loop to only delay if the
transmitter is not ready.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/serial/8250.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1867,15 +1867,17 @@ static void wait_for_xmitr(struct uart_8
unsigned int status, tmout = 10000;
/* Wait up to 10ms for the character(s) to be sent. */
- do {
+ for (;;) {
status = serial_in(up, UART_LSR);
up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
+ if ((status & bits) == bits)
+ break;
if (--tmout == 0)
break;
udelay(1);
- } while ((status & bits) != bits);
+ }
/* Wait up to 1s for flow control if necessary */
if (up->port.flags & UPF_CONS_FLOW) {
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