Fix and speed up the poll loop.
The delay(10) was just too much of a delay, I changed it to a yield().
The large delay was causing the NACK in the address state to be
missed, so instead of getting a NACK, we were getting a timeout.
I also shortened the timeout to HZ/5, as 1 second was excessive.
Signed-off-by: Ben Gardner <bgardner at wabtec.com>
-------------- next part --------------
drivers/i2c/busses/scx200_acb.c | 13 ++-----------
1 files changed, 2 insertions(+), 11 deletions(-)
--- linux-2.6.15-rc5-mm1.orig/drivers/i2c/busses/scx200_acb.c
+++ linux-2.6.15-rc5-mm1/drivers/i2c/busses/scx200_acb.c
@@ -47,10 +47,7 @@ static int base[MAX_DEVICES] = { 0x820,
module_param_array(base, int, NULL, 0);
MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
-/* The hardware supports interrupt driven mode too, but I haven't
- implemented that. */
-#define POLLED_MODE 1
-#define POLL_TIMEOUT (HZ)
+#define POLL_TIMEOUT (HZ/5)
enum scx200_acb_state {
state_idle,
@@ -223,7 +220,6 @@ static void scx200_acb_machine(struct sc
iface->needs_reset = 1;
}
-#ifdef POLLED_MODE
static void scx200_acb_poll(struct scx200_acb_iface *iface)
{
u8 status;
@@ -236,7 +232,7 @@ static void scx200_acb_poll(struct scx20
scx200_acb_machine(iface, status);
return;
}
- msleep(10);
+ yield();
}
dev_err(&iface->adapter.dev, "timeout in state %s\n",
@@ -246,7 +242,6 @@ static void scx200_acb_poll(struct scx20
iface->result = -EIO;
iface->needs_reset = 1;
}
-#endif /* POLLED_MODE */
static void scx200_acb_reset(struct scx200_acb_iface *iface)
{
@@ -341,12 +336,8 @@ static s32 scx200_acb_smbus_xfer(struct
else
iface->state = state_address;
-#ifdef POLLED_MODE
while (iface->state != state_idle)
scx200_acb_poll(iface);
-#else /* POLLED_MODE */
-#error Interrupt driven mode not implemented
-#endif /* POLLED_MODE */
if (iface->needs_reset)
scx200_acb_reset(iface);
