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authorTimur Tabi <timur@freescale.com>2009-02-06 08:00:37 -0600
committerKumar Gala <galak@kernel.crashing.org>2009-03-09 09:25:34 -0500
commit1ab082d7cbd0f34e39a5396cc6340c00bc5d66ef (patch)
treeae55102ad5c2ef84ca0462f29e6adf3607daf9b7 /drivers/i2c
parent652e8f8d579d61745094e36b4ff085026a332e73 (diff)
i2c-mpc: do not allow interruptions when waiting for I2C to complete
The i2c_wait() function is using wait_event_interruptible_timeout() to wait for the I2C controller to signal that it has completed an I2C bus operation. If the process that causes the I2C operation terminated abruptly, the wait will be interrupted, returning an error. It is better to let the I2C operation finished before the process exits. It is safe to use wait_event_timeout() instead, because the timeout will allow the process to exit if the I2C bus hangs. It's also better to allow the I2C operation to finish, because unacknowledged I2C operations can cause the I2C bus to hang. Signed-off-by: Timur Tabi <timur@freescale.com> Acked-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-mpc.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index aedbbe6618d..3163eab3f60 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -70,7 +70,7 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
/* Read again to allow register to stabilise */
i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
writeb(0, i2c->base + MPC_I2C_SR);
- wake_up_interruptible(&i2c->queue);
+ wake_up(&i2c->queue);
}
return IRQ_HANDLED;
}
@@ -115,13 +115,10 @@ static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
writeb(0, i2c->base + MPC_I2C_SR);
} else {
/* Interrupt mode */
- result = wait_event_interruptible_timeout(i2c->queue,
+ result = wait_event_timeout(i2c->queue,
(i2c->interrupt & CSR_MIF), timeout * HZ);
- if (unlikely(result < 0)) {
- pr_debug("I2C: wait interrupted\n");
- writeccr(i2c, 0);
- } else if (unlikely(!(i2c->interrupt & CSR_MIF))) {
+ if (unlikely(!(i2c->interrupt & CSR_MIF))) {
pr_debug("I2C: wait timeout\n");
writeccr(i2c, 0);
result = -ETIMEDOUT;