[PATCH] tpm: update to use wait_event calls

Kylene Jo Hall
2006-04-11T20:15:13Z

On Mon, 2006-04-10 at 15:03 -0700, Andrew Morton wrote:
>
> > + interruptible_sleep_on_timeout(&chip->vendor.int_queue,
> > + HZ *
> > + chip->vendor.timeout_a /
> > + 1000);
> >
> > ...
> >
> > + interruptible_sleep_on_timeout(queue, HZ * timeout / 1000);
>
> Please don't use the sleep_on functions. They are racy unless (iirc) both
> the waker and wakee are holding lock_kernel(). If the race hits, we miss a
> wakeup.
>
> These should be converted to the not-racy wait_event_interruptible().

Changed in this patch.

Use wait_event_interruptible_timeout in place of
interruptible_sleep_on_timeout due to its racy nature.

Signed-off-by: Kylie Hall <kjhall@us.ibm.com>
---
drivers/char/tpm/tpm_tis.c | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)

--- linux-2.6.17-rc1/drivers/char/tpm/tpm_tis.c 2006-04-11 12:18:35.573996500 -0500
+++ linux-2.6.16-44/drivers/char/tpm/tpm_tis.c 2006-04-11 14:00:04.341229250 -0500
@@ -95,10 +95,10 @@ static int request_locality(struct tpm_c
chip->vendor.iobase + TPM_ACCESS(l));

if (chip->vendor.irq) {
- interruptible_sleep_on_timeout(&chip->vendor.int_queue,
- HZ *
- chip->vendor.timeout_a /
- 1000);
+ wait_event_interruptible_timeout(chip->vendor.int_queue,
+ (check_locality(chip, l) >= 0),
+ HZ * chip->vendor.timeout_a /
+ 1000);
if (check_locality(chip, l) >= 0)
return l;

@@ -150,7 +150,7 @@ static int get_burstcount(struct tpm_chi
}

static int wait_for_stat(struct tpm_chip *chip, u8 mask, u32 timeout,
- wait_queue_head_t * queue)
+ wait_queue_head_t *queue)
{
unsigned long stop;
u8 status;
@@ -161,7 +161,10 @@ static int wait_for_stat(struct tpm_chip
return 0;

if (chip->vendor.irq) {
- interruptible_sleep_on_timeout(queue, HZ * timeout / 1000);
+ wait_event_interruptible_timeout(*queue,
+ ((tpm_tis_status(chip) &
+ mask) == mask),
+ HZ * timeout / 1000);
status = tpm_tis_status(chip);
if ((status & mask) == mask)
return 0;