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authorPatrick Gefre <pfg@sgi.com>2005-05-01 08:59:21 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-05-01 08:59:21 -0700
commit6cb2875f8d7e392982229094ad3b6d2f213f48da (patch)
treef763e4f5ecc499d9d62007e7bb6aadd9455db84e /drivers/serial
parent149733d4e274ce1add3399cabdb243116ebfdf79 (diff)
[PATCH] Altix ioc4 serial - set a better timeout/threshold
Set the timeout and threshold to better values. Signed-off-by: Patrick Gefre <pfg@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/serial')
-rw-r--r--drivers/serial/ioc4_serial.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/serial/ioc4_serial.c b/drivers/serial/ioc4_serial.c
index f94d2e712ca..d3f4542616c 100644
--- a/drivers/serial/ioc4_serial.c
+++ b/drivers/serial/ioc4_serial.c
@@ -1272,8 +1272,9 @@ static inline int set_rx_timeout(struct ioc4_port *port, int timeout)
* and set the rx threshold to that amount. There are 4 chars
* per ring entry, so we'll divide the number of chars that will
* arrive in timeout by 4.
+ * So .... timeout * baud / 10 / HZ / 4, with HZ = 100.
*/
- threshold = timeout * port->ip_baud / 10 / HZ / 4;
+ threshold = timeout * port->ip_baud / 4000;
if (threshold == 0)
threshold = 1; /* otherwise we'll intr all the time! */
@@ -1285,8 +1286,10 @@ static inline int set_rx_timeout(struct ioc4_port *port, int timeout)
writel(port->ip_sscr, &port->ip_serial_regs->sscr);
- /* Now set the rx timeout to the given value */
- timeout = timeout * IOC4_SRTR_HZ / HZ;
+ /* Now set the rx timeout to the given value
+ * again timeout * IOC4_SRTR_HZ / HZ
+ */
+ timeout = timeout * IOC4_SRTR_HZ / 100;
if (timeout > IOC4_SRTR_CNT)
timeout = IOC4_SRTR_CNT;
@@ -1380,7 +1383,7 @@ config_port(struct ioc4_port *port,
if (port->ip_tx_lowat == 0)
port->ip_tx_lowat = 1;
- set_rx_timeout(port, port->ip_rx_timeout);
+ set_rx_timeout(port, 2);
return 0;
}