[PATCH] serial: Z85C30: BCM1480: loops should end at 0

Roel Kluin
2009-02-08T15:40:53Z

With a postfix decrement 'loops' reach -1, not 0, which is subsequently
returned. In drivers/serial/zs.c, line 1137 it is considered as a boolean with 0
as failure:

if (zs_transmit_drain(zport, irq))
write_zsdata(zport, ch);

so to use it as such loops should end at 0 after the loop rather than -1.
This also fix similar issues in other functions.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
Another solution would be to change the test at drivers/serial/zs.c, line 1137:

if (zs_transmit_drain(zport, irq) == -1)

Is that preferred?

drivers/serial/sb1250-duart.c | 6 +++---
drivers/serial/zs.c | 6 +++---
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/serial/sb1250-duart.c b/drivers/serial/sb1250-duart.c
index a4fb343..319e8b8 100644
--- a/drivers/serial/sb1250-duart.c
+++ b/drivers/serial/sb1250-duart.c
@@ -204,7 +204,7 @@ static int sbd_receive_drain(struct sbd_port *sport)
{
int loops = 10000;

- while (sbd_receive_ready(sport) && loops--)
+ while (sbd_receive_ready(sport) && --loops)
read_sbdchn(sport, R_DUART_RX_HOLD);
return loops;
}
@@ -218,7 +218,7 @@ static int __maybe_unused sbd_transmit_drain(struct sbd_port *sport)
{
int loops = 10000;

- while (!sbd_transmit_ready(sport) && loops--)
+ while (!sbd_transmit_ready(sport) && --loops)
udelay(2);
return loops;
}
@@ -232,7 +232,7 @@ static int sbd_line_drain(struct sbd_port *sport)
{
int loops = 10000;

- while (!sbd_transmit_empty(sport) && loops--)
+ while (!sbd_transmit_empty(sport) && --loops)
udelay(2);
return loops;
}
diff --git a/drivers/serial/zs.c b/drivers/serial/zs.c
index 9e6a873..d8c2809 100644
--- a/drivers/serial/zs.c
+++ b/drivers/serial/zs.c
@@ -231,7 +231,7 @@ static int zs_receive_drain(struct zs_port *zport)
{
int loops = 10000;

- while ((read_zsreg(zport, R0) & Rx_CH_AV) && loops--)
+ while ((read_zsreg(zport, R0) & Rx_CH_AV) && --loops)
read_zsdata(zport);
return loops;
}
@@ -241,7 +241,7 @@ static int zs_transmit_drain(struct zs_port *zport, int irq)
struct zs_scc *scc = zport->scc;
int loops = 10000;

- while (!(read_zsreg(zport, R0) & Tx_BUF_EMP) && loops--) {
+ while (!(read_zsreg(zport, R0) & Tx_BUF_EMP) && --loops) {
zs_spin_unlock_cond_irq(&scc->zlock, irq);
udelay(2);
zs_spin_lock_cond_irq(&scc->zlock, irq);
@@ -254,7 +254,7 @@ static int zs_line_drain(struct zs_port *zport, int irq)
struct zs_scc *scc = zport->scc;
int loops = 10000;

- while (!(read_zsreg(zport, R1) & ALL_SNT) && loops--) {
+ while (!(read_zsreg(zport, R1) & ALL_SNT) && --loops) {
zs_spin_unlock_cond_irq(&scc->zlock, irq);
udelay(2);
zs_spin_lock_cond_irq(&scc->zlock, irq);