From a7b66822b20f67f106690d0acee3d0ba667fd9bb Mon Sep 17 00:00:00 2001 From: Stefan Berger Date: Wed, 30 Mar 2011 12:13:32 -0400 Subject: tpm_tis: Fix the probing for interrupts This patch fixes several aspects of the probing for interrupts. This patch reads the TPM's timeouts before probing for the interrupts. The tpm_get_timeouts() function is invoked in polling mode and gets the proper timeouts from the TPM so that we don't need to fall back to 2 minutes timeouts for short duration commands while the interrupt probing is happening. This patch introduces a variable probed_irq into the vendor structure that gets the irq number if an interrupt is received while the the tpm_gen_interrupt() function is run in polling mode during interrupt probing. Previously some parts of tpm_gen_interrupt() were run in polling mode, then the irq variable was set in the interrupt handler when an interrupt was received and execution of tpm_gen_interrupt() ended up switching over to interrupt mode. tpm_gen_interrupt() execution ended up on an event queue where it eventually timed out since the probing handler doesn't wake any queues. Before calling into free_irq() clear all interrupt flags that may have been set by the TPM. The reason is that free_irq() will call into the probing interrupt handler and may otherwise fool us into thinking that a real interrupt happened (because we see the flags as being set) while the TPM's interrupt line is not even connected to anything on the motherboard. This solves a problem on one machine I did testing on (Thinkpad T60). If a TPM claims to use a specifc interrupt, the probing is done as well to verify that the interrupt is actually working. If a TPM indicates that it does not use a specific interrupt (returns '0'), probe all interrupts from 3 to 15. Signed-off-by: Stefan Berger Signed-off-by: Rajiv Andrade --- drivers/char/tpm/tpm.h | 1 + drivers/char/tpm/tpm_tis.c | 33 +++++++++++++++++++++++++++------ 2 files changed, 28 insertions(+), 6 deletions(-) (limited to 'drivers') diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index c5e01c556233..9c4163cfa3ce 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -71,6 +71,7 @@ struct tpm_vendor_specific { unsigned long base; /* TPM base address */ int irq; + int probed_irq; int region_size; int have_region; diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index b97ce2b205d7..47517e49d2be 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -438,7 +438,7 @@ static irqreturn_t tis_int_probe(int irq, void *dev_id) if (interrupt == 0) return IRQ_NONE; - chip->vendor.irq = irq; + chip->vendor.probed_irq = irq; /* Clear interrupts handled with TPM_EOI */ iowrite32(interrupt, @@ -486,7 +486,7 @@ static int tpm_tis_init(struct device *dev, resource_size_t start, resource_size_t len, unsigned int irq) { u32 vendor, intfcaps, intmask; - int rc, i; + int rc, i, irq_s, irq_e; struct tpm_chip *chip; if (!(chip = tpm_register_hardware(dev, &tpm_tis))) @@ -544,6 +544,9 @@ static int tpm_tis_init(struct device *dev, resource_size_t start, if (intfcaps & TPM_INTF_DATA_AVAIL_INT) dev_dbg(dev, "\tData Avail Int Support\n"); + /* get the timeouts before testing for irqs */ + tpm_get_timeouts(chip); + /* INTERRUPT Setup */ init_waitqueue_head(&chip->vendor.read_queue); init_waitqueue_head(&chip->vendor.int_queue); @@ -562,13 +565,19 @@ static int tpm_tis_init(struct device *dev, resource_size_t start, if (interrupts) chip->vendor.irq = irq; if (interrupts && !chip->vendor.irq) { - chip->vendor.irq = + irq_s = ioread8(chip->vendor.iobase + TPM_INT_VECTOR(chip->vendor.locality)); + if (irq_s) { + irq_e = irq_s; + } else { + irq_s = 3; + irq_e = 15; + } - for (i = 3; i < 16 && chip->vendor.irq == 0; i++) { + for (i = irq_s; i <= irq_e && chip->vendor.irq == 0; i++) { iowrite8(i, chip->vendor.iobase + - TPM_INT_VECTOR(chip->vendor.locality)); + TPM_INT_VECTOR(chip->vendor.locality)); if (request_irq (i, tis_int_probe, IRQF_SHARED, chip->vendor.miscdev.name, chip) != 0) { @@ -590,9 +599,22 @@ static int tpm_tis_init(struct device *dev, resource_size_t start, chip->vendor.iobase + TPM_INT_ENABLE(chip->vendor.locality)); + chip->vendor.probed_irq = 0; + /* Generate Interrupts */ tpm_gen_interrupt(chip); + chip->vendor.irq = chip->vendor.probed_irq; + + /* free_irq will call into tis_int_probe; + clear all irqs we haven't seen while doing + tpm_gen_interrupt */ + iowrite32(ioread32 + (chip->vendor.iobase + + TPM_INT_STATUS(chip->vendor.locality)), + chip->vendor.iobase + + TPM_INT_STATUS(chip->vendor.locality)); + /* Turn off */ iowrite32(intmask, chip->vendor.iobase + @@ -631,7 +653,6 @@ static int tpm_tis_init(struct device *dev, resource_size_t start, list_add(&chip->vendor.list, &tis_chips); spin_unlock(&tis_lock); - tpm_get_timeouts(chip); tpm_continue_selftest(chip); return 0; -- cgit v1.2.3