diff options
| author | David Daney <ddaney@caviumnetworks.com> | 2010-10-05 11:40:07 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-10-22 10:20:06 -0700 |
| commit | 97d303b7657c1a45c158d002f829ff69196c493d (patch) | |
| tree | ad796eebea4bb22064e87dde1518ca935cca2dcd /drivers/serial/8250.c | |
| parent | fd8b6cb4d820c4a717af1a0ac3ee387fd84571cf (diff) | |
| download | lwn-97d303b7657c1a45c158d002f829ff69196c493d.tar.gz lwn-97d303b7657c1a45c158d002f829ff69196c493d.zip | |
serial: 8250: Don't delay after transmitter is ready.
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>
Diffstat (limited to 'drivers/serial/8250.c')
| -rw-r--r-- | drivers/serial/8250.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 24110f6f61e0..31b8cca179cd 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1867,15 +1867,17 @@ static void wait_for_xmitr(struct uart_8250_port *up, int bits) 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) { |