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authorNishanth Aravamudan <nacc@us.ibm.com>2005-06-23 22:01:47 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-24 00:05:24 -0700
commit700d8bdcd0fa815b08638b1e4d43b66d60cc6a8d (patch)
treec3defbf1cb77b9290a002cff04e1b2f054dfcb05 /drivers/char/tpm/tpm.c
parent6a94f9209762a6eb286f668e1346ad87985cc765 (diff)
[PATCH] char/tpm: use msleep(), clean-up timers,
The TPM driver unnecessarily uses timers when it simply needs to maintain a maximum delay via time_before(). msleep() is used instead of schedule_timeout() to guarantee the task delays as expected. While compile-testing, I found a typo in the driver, using tpm_chp instead of tpm_chip. Remove the now unused timer callback function and change TPM_TIMEOUT's units to milliseconds. Patch is compile-tested. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Acked-by: Kylene Hall <kjhall@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/char/tpm/tpm.c')
-rw-r--r--drivers/char/tpm/tpm.c35
1 files changed, 7 insertions, 28 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 8ce508b2986..c937ea2bcdb 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -19,7 +19,7 @@
*
* Note, the TPM chip is not interrupt driven (only polling)
* and can have very long timeouts (minutes!). Hence the unusual
- * calls to schedule_timeout.
+ * calls to msleep.
*
*/
@@ -52,14 +52,6 @@ static void user_reader_timeout(unsigned long ptr)
up(&chip->buffer_mutex);
}
-void tpm_time_expired(unsigned long ptr)
-{
- int *exp = (int *) ptr;
- *exp = 1;
-}
-
-EXPORT_SYMBOL_GPL(tpm_time_expired);
-
/*
* Initialize the LPC bus and enable the TPM ports
*/
@@ -135,6 +127,7 @@ static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
ssize_t len;
u32 count;
__be32 *native_size;
+ unsigned long stop;
native_size = (__force __be32 *) (buf + 2);
count = be32_to_cpu(*native_size);
@@ -155,28 +148,16 @@ static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
return len;
}
- down(&chip->timer_manipulation_mutex);
- chip->time_expired = 0;
- init_timer(&chip->device_timer);
- chip->device_timer.function = tpm_time_expired;
- chip->device_timer.expires = jiffies + 2 * 60 * HZ;
- chip->device_timer.data = (unsigned long) &chip->time_expired;
- add_timer(&chip->device_timer);
- up(&chip->timer_manipulation_mutex);
-
+ stop = jiffies + 2 * 60 * HZ;
do {
u8 status = inb(chip->vendor->base + 1);
if ((status & chip->vendor->req_complete_mask) ==
chip->vendor->req_complete_val) {
- down(&chip->timer_manipulation_mutex);
- del_singleshot_timer_sync(&chip->device_timer);
- up(&chip->timer_manipulation_mutex);
goto out_recv;
}
- set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_timeout(TPM_TIMEOUT);
+ msleep(TPM_TIMEOUT); /* CHECK */
rmb();
- } while (!chip->time_expired);
+ } while (time_before(jiffies, stop));
chip->vendor->cancel(chip);
@@ -453,10 +434,8 @@ ssize_t tpm_write(struct file * file, const char __user * buf,
/* cannot perform a write until the read has cleared
either via tpm_read or a user_read_timer timeout */
- while (atomic_read(&chip->data_pending) != 0) {
- set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_timeout(TPM_TIMEOUT);
- }
+ while (atomic_read(&chip->data_pending) != 0)
+ msleep(TPM_TIMEOUT);
down(&chip->buffer_mutex);