From 700d8bdcd0fa815b08638b1e4d43b66d60cc6a8d Mon Sep 17 00:00:00 2001 From: Nishanth Aravamudan Date: Thu, 23 Jun 2005 22:01:47 -0700 Subject: [PATCH] [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 Acked-by: Kylene Hall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/tpm/tpm.c | 35 +++++++---------------------------- drivers/char/tpm/tpm.h | 3 +-- drivers/char/tpm/tpm_nsc.c | 32 ++++++++++---------------------- 3 files changed, 18 insertions(+), 52 deletions(-) diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 8ce508b29865..c937ea2bcdbc 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 de0c796fce80..3c4ee433ec7f 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -25,7 +25,7 @@ #include #include -#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 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; -- 2.30.2