I2C-MPC: use wait_event_interruptible_timeout

I've changed the i2c-mpc.c driver to use wait_event_interruptible_timeout

Can you take a look and let me know if this looks good. I'm going to have some other changes to the driver to handle moving it from an OCP based driver to using platform_device.

thanks

- kumar

=== drivers/i2c/busses/i2c-mpc.c 1.2 vs edited ==--- 1.2/drivers/i2c/busses/i2c-mpc.c 2004-09-16 18:37:31 -05:00
+++ edited/drivers/i2c/busses/i2c-mpc.c 2005-01-13 16:41:57 -06:00
@@ -75,7 +75,6 @@

static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing) {
- DECLARE_WAITQUEUE(wait, current);
unsigned long orig_jiffies = jiffies;
u32 x;
int result = 0;
@@ -92,28 +91,22 @@
x = readb(i2c->base + MPC_I2C_SR);
writeb(0, i2c->base + MPC_I2C_SR);
} else {
- set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&i2c->queue, &wait);
- while (!(i2c->interrupt & CSR_MIF)) {
- if (signal_pending(current)) {
- pr_debug("I2C: Interrupted\n");
- result = -EINTR;
- break;
- }
- if (time_after(jiffies, orig_jiffies + timeout)) {
- pr_debug("I2C: timeout\n");
- result = -EIO;
- break;
- }
- msleep_interruptible(jiffies_to_msecs(timeout));
+ /* Interrupt mode */
+ result = wait_event_interruptible_timeout(i2c->queue,
+ (i2c->interrupt & CSR_MIF), timeout * HZ);
+
+ if (unlikely(result < 0))
+ pr_debug("I2C: wait interrupted\n");
+ else if (unlikely(!(i2c->interrupt & CSR_MIF))) {
+ pr_debug("I2C: wait timeout\n");
+ result = -ETIMEDOUT;
}
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&i2c->queue, &wait);
+
x = i2c->interrupt;
i2c->interrupt = 0;
}

- if (result < -0)
+ if (result < 0)
return result;

if (!(x & CSR_MCF)) {
@@ -165,7 +158,7 @@
const u8 * data, int length, int restart)
{
int i;
- unsigned timeout = HZ;
+ unsigned timeout = i2c->adap.timeout;
u32 flags = restart ? CCR_RSTA : 0;

/* Start with MEN */
@@ -193,7 +186,7 @@
static int mpc_read(struct mpc_i2c *i2c, int target,
u8 * data, int length, int restart)
{
- unsigned timeout = HZ;
+ unsigned timeout = i2c->adap.timeout;
int i;
u32 flags = restart ? CCR_RSTA : 0;

@@ -302,6 +295,7 @@
if (!(i2c = kmalloc(sizeof(*i2c), GFP_KERNEL))) {
return -ENOMEM;
}
+ memset(i2c, 0, sizeof(*i2c));
i2c->ocpdef = ocp->def; init_waitqueue_head(&i2c->queue);

Looks sane to me. You've tested this out? If you're comfortable with it, care to resend it with a "Signed-off-by:" line to me so I can apply it to the kernel tree?

thanks,

greg k-h

Greg,

I will send it in a more "official" way shortly. I will also have some patches to allow building the driver for OCP (on-chip peripheral, the old PPC way of doing drivers) or as a platform_device. This is meant to act as an interim until we can convert all the various PPC sub-archs to use platform_devices (at which point, I will kill the OCP side of the driver).

- kumar