[PATCH] tpm: locking fix
Use schedule_work() to avoid down()-in-timer-handler problem.
Signed-off-by: Kylene Hall <kjhall@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 1a53da9..0b283d2 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -43,6 +43,13 @@
{
struct tpm_chip *chip = (struct tpm_chip *) ptr;
+ schedule_work(&chip->work);
+}
+
+static void timeout_work(void * ptr)
+{
+ struct tpm_chip *chip = ptr;
+
down(&chip->buffer_mutex);
atomic_set(&chip->data_pending, 0);
memset(chip->data_buffer, 0, TPM_BUFSIZE);
@@ -527,6 +534,8 @@
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 --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index ad51c65..159882c 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -77,6 +77,7 @@
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;