USB: serial: keyspan_pda: increase transmitter threshold

Increase the transmitter threshold so that writing isn't resumed until
128 bytes are available in the device buffer thereby allowing for larger
and more efficient transfers.

Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index b3fb2ecefb315ee73e1ecb35603078871eb40728..3816bbc928b2711a207a47600d56a38a21fd68ca 100644 (file)
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -40,7 +40,7 @@
 #define DRIVER_AUTHOR "Brian Warner <warner@lothar.com>"
 #define DRIVER_DESC "USB Keyspan PDA Converter driver"
 
-#define KEYSPAN_TX_THRESHOLD   16
+#define KEYSPAN_TX_THRESHOLD   128
 
 struct keyspan_pda_private {
        int                     tx_room;