[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>

1 files changed, 10 insertions, 22 deletions

diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
index 9cce833a0923..6e5ffcacea60 100644
--- a/drivers/char/tpm/tpm_nsc.c
+++ b/drivers/char/tpm/tpm_nsc.c
@@ -55,10 +55,7 @@
  */
 static int wait_for_stat(struct tpm_chip *chip, u8 mask, u8 val, u8 * data)
 {
-        int expired = 0;
-        struct timer_list status_timer =
-            TIMER_INITIALIZER(tpm_time_expired, jiffies + 10 * HZ,
-                              (unsigned long) &expired);
+        unsigned long stop;
 
         /* status immediately available check */
         *data = inb(chip->vendor->base + NSC_STATUS);
@@ -66,17 +63,14 @@ static int wait_for_stat(struct tpm_chip *chip, u8 mask, u8 val, u8 * data)
                 return 0;
 
         /* wait for status */
-        add_timer(&status_timer);
+        stop = jiffies + 10 * HZ;
         do {
-                set_current_state(TASK_UNINTERRUPTIBLE);
-                schedule_timeout(TPM_TIMEOUT);
+                msleep(TPM_TIMEOUT);
                 *data = inb(chip->vendor->base + 1);
-                if ((*data & mask) == val) {
-                        del_singleshot_timer_sync(&status_timer);
+                if ((*data & mask) == val)
                         return 0;
-                }
         }
-        while (!expired);
+        while (time_before(jiffies, stop));
 
         return -EBUSY;
 }
@@ -84,10 +78,7 @@ static int wait_for_stat(struct tpm_chip *chip, u8 mask, u8 val, u8 * data)
 static int nsc_wait_for_ready(struct tpm_chip *chip)
 {
         int status;
-        int expired = 0;
-        struct timer_list status_timer =
-            TIMER_INITIALIZER(tpm_time_expired, jiffies + 100,
-                              (unsigned long) &expired);
+        unsigned long stop;
 
         /* status immediately available check */
         status = inb(chip->vendor->base + NSC_STATUS);
@@ -97,19 +88,16 @@ static int nsc_wait_for_ready(struct tpm_chip *chip)
                 return 0;
 
         /* wait for status */
-        add_timer(&status_timer);
+        stop = jiffies + 100;
         do {
-                set_current_state(TASK_UNINTERRUPTIBLE);
-                schedule_timeout(TPM_TIMEOUT);
+                msleep(TPM_TIMEOUT);
                 status = inb(chip->vendor->base + NSC_STATUS);
                 if (status & NSC_STATUS_OBF)
                         status = inb(chip->vendor->base + NSC_DATA);
-                if (status & NSC_STATUS_RDY) {
-                        del_singleshot_timer_sync(&status_timer);
+                if (status & NSC_STATUS_RDY)
                         return 0;
-                }
         }
-        while (!expired);
+        while (time_before(jiffies, stop));
 
         dev_info(&chip->pci_dev->dev, "wait for ready failed\n");
         return -EBUSY;