> >
> > b) user_reader_timeout does down() from within a timer handler! That's
> > deadlocky and is illegal - timer handlers are run from interrupt
> > context.
> >
> > This should have generated a storm of runtime warnings if tested with
> > CONFIG_PREEMPT and CONFIG_DEBUG_SPINLOCK_SLEEP. Developers really should
> > enable all the kernel debug options during development - they find bugs.
> >
> > Suggest you convert this to using schedule_work() or
> > schedule_delayed_work().
> >
> I'll look into this.
Addressed this timer/interrupt/spinlock issue with schedule_work.
Signed-off-by: Kylene Hall <[email protected]>
---
diff -urpN --exclude='*.o' --exclude='*.ko' --exclude='*.orig' --exclude='*mod*' --exclude='.*' --exclude='tpm_*' --exclude='*~' --exclude='*.rej' linux-2.6.14/drivers/char/tpm/tpm.c linux-2.6.14-rc4-tpm/drivers/char/tpm/tpm.c
--- linux-2.6.14/drivers/char/tpm/tpm.c 2005-11-11 14:09:47.000000000 -0600
+++ linux-2.6.14-rc4-tpm/drivers/char/tpm/tpm.c 2005-11-11 15:40:34.000000000 -0600
@@ -43,6 +43,13 @@ static void user_reader_timeout(unsigned
{
struct tpm_chip *chip = (struct tpm_chip *) ptr;
+ schedule_work(&chip->work);
+}
+
+static void timeout_work(void * ptr)
+{
+ struct tpm_chip *chip = (struct tpm_chip*) ptr;
+
down(&chip->buffer_mutex);
atomic_set(&chip->data_pending, 0);
memset(chip->data_buffer, 0, TPM_BUFSIZE);
@@ -527,6 +535,8 @@ int tpm_register_hardware(struct device
init_MUTEX(&chip->tpm_mutex);
INIT_LIST_HEAD(&chip->list);
+ INIT_WORK(&chip->work, timeout_work, chip);
+
init_timer(&chip->user_read_timer);
chip->user_read_timer.function = user_reader_timeout;
chip->user_read_timer.data = (unsigned long) chip;
diff -urpN --exclude='*.o' --exclude='*.ko' --exclude='*.orig' --exclude='*mod*' --exclude='.*' --exclude='tpm_*' --exclude='*~' --exclude='*.rej' linux-2.6.14/drivers/char/tpm/tpm.h linux-2.6.14-rc4-tpm/drivers/char/tpm/tpm.h
--- linux-2.6.14/drivers/char/tpm/tpm.h 2005-11-11 16:44:23.000000000 -0600
+++ linux-2.6.14-rc4-tpm/drivers/char/tpm/tpm.h 2005-11-11 15:39:03.000000000 -0600
@@ -77,6 +77,7 @@ struct tpm_chip {
struct semaphore buffer_mutex;
struct timer_list user_read_timer; /* user needs to claim result */
+ struct work_struct work;
struct semaphore tpm_mutex; /* tpm is processing */
struct tpm_vendor_specific *vendor;
-
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