Messages in this thread | | | Date | Tue, 11 Apr 2006 13:31:54 -0700 | From | "Nish Aravamudan" <> | Subject | Re: [PATCH] tpm: update to use wait_event calls |
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On 4/11/06, Kylene Jo Hall <kjhall@us.ibm.com> wrote: > 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;
Rather than check the condition you slept on right away, couldn't you just store the return value of wait_event_interruptible_timeout()? If it's positive, the condition should be true, if it's negative, then you got a signal, if it's 0, then you timed out. Same would go for the other change.
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