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authorNishanth Aravamudan <nacc@us.ibm.com>2005-06-24 05:01:47 (GMT)
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-24 07:05:24 (GMT)
commit700d8bdcd0fa815b08638b1e4d43b66d60cc6a8d (patch)
treec3defbf1cb77b9290a002cff04e1b2f054dfcb05 /drivers
parent6a94f9209762a6eb286f668e1346ad87985cc765 (diff)
downloadlinux-700d8bdcd0fa815b08638b1e4d43b66d60cc6a8d.tar.xz
[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')
-rw-r--r--drivers/char/tpm/tpm.c35
-rw-r--r--drivers/char/tpm/tpm.h3
-rw-r--r--drivers/char/tpm/tpm_nsc.c32
3 files changed, 18 insertions, 52 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 8ce508b..c937ea2 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);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index de0c796..3c4ee43 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -25,7 +25,7 @@
#include <linux/fs.h>
#include <linux/miscdevice.h>
-#define TPM_TIMEOUT msecs_to_jiffies(5)
+#define TPM_TIMEOUT 5 /* msecs */
/* TPM addresses */
#define TPM_ADDR 0x4E
@@ -78,7 +78,6 @@ static inline void tpm_write_index(int index, int value)
outb(value & 0xFF, TPM_DATA);
}
-extern void tpm_time_expired(unsigned long);
extern int tpm_lpc_bus_init(struct pci_dev *, u16);
extern int tpm_register_hardware(struct pci_dev *,
diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
index 9cce833a..6e5ffca 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;