[PATCH] Refuse activation of tpm_tis driver if TPM is not working correctly

[PATCH] Refuse activation of tpm_tis driver if TPM is not working correctly

[Stefan Berger]

Refuse activation of tpm_tis driver if the TPM is found not to be
working correctly. This prevents suspend/resume problems for me on
Lenovo W500 and T61p.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

---
 drivers/char/tpm/tpm_tis.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 3f4051a..7f2761d 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -549,6 +549,7 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
 	u32 vendor, intfcaps, intmask;
 	int rc, i, irq_s, irq_e;
 	struct tpm_chip *chip;
+	u8 digest[TPM_DIGEST_SIZE];
 
 	if (!(chip = tpm_register_hardware(dev, &tpm_tis)))
 		return -ENODEV;
@@ -616,6 +617,18 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
 	/* get the timeouts before testing for irqs */
 	tpm_get_timeouts(chip);
 
+	/* test for correctly working TPM; refuse driver if not working 
+	   to prevent suspend/resume problems */
+	rc = tpm_pcr_read(chip->dev_num, 0, digest);
+	if (rc != 0) {
+		dev_err(dev, "Could not read PCR 0. "
+			"TPM is not working correctly.\n");
+		dev_err(dev, "Was machine previously suspended without TPM "
+			"driver present?\n");
+		rc = -ENODEV;
+		goto out_err;
+	}
+
 	/* INTERRUPT Setup */
 	init_waitqueue_head(&chip->vendor.read_queue);
 	init_waitqueue_head(&chip->vendor.int_queue);
-- 
1.7.6.4

Re: [PATCH] Refuse activation of tpm_tis driver if TPM is not working correctly

[Rajiv Andrade]

On 10/10/11 09:16, Stefan Berger wrote:
> Refuse activation of tpm_tis driver if the TPM is found not to be
> working correctly. This prevents suspend/resume problems for me on
> Lenovo W500 and T61p.
>
> Signed-off-by: Stefan Berger<stefanb@linux.vnet.ibm.com>
Testing and trying to reproduce it here.

Rajiv
>
> ---
>   drivers/char/tpm/tpm_tis.c |   13 +++++++++++++
>   1 files changed, 13 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
> index 3f4051a..7f2761d 100644
> --- a/drivers/char/tpm/tpm_tis.c
> +++ b/drivers/char/tpm/tpm_tis.c
> @@ -549,6 +549,7 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
>   	u32 vendor, intfcaps, intmask;
>   	int rc, i, irq_s, irq_e;
>   	struct tpm_chip *chip;
> +	u8 digest[TPM_DIGEST_SIZE];
>
>   	if (!(chip = tpm_register_hardware(dev,&tpm_tis)))
>   		return -ENODEV;
> @@ -616,6 +617,18 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
>   	/* get the timeouts before testing for irqs */
>   	tpm_get_timeouts(chip);
>
> +	/* test for correctly working TPM; refuse driver if not working
> +	   to prevent suspend/resume problems */
> +	rc = tpm_pcr_read(chip->dev_num, 0, digest);
> +	if (rc != 0) {
> +		dev_err(dev, "Could not read PCR 0. "
> +			"TPM is not working correctly.\n");
> +		dev_err(dev, "Was machine previously suspended without TPM "
> +			"driver present?\n");
> +		rc = -ENODEV;
> +		goto out_err;
> +	}
> +
>   	/* INTERRUPT Setup */
>   	init_waitqueue_head(&chip->vendor.read_queue);
>   	init_waitqueue_head(&chip->vendor.int_queue);

Re: [tpmdd-devel] [PATCH] Refuse activation of tpm_tis driver if TPM is not working correctly

[Rajiv Andrade]

On 10/10/11 10:04, Rajiv Andrade wrote:
> On 10/10/11 09:16, Stefan Berger wrote:
>> Refuse activation of tpm_tis driver if the TPM is found not to be
>> working correctly. This prevents suspend/resume problems for me on
>> Lenovo W500 and T61p.
>>
>> Signed-off-by: Stefan Berger<stefanb@linux.vnet.ibm.com>
> Testing and trying to reproduce it here.
Yes, for some yet unknown reason the TPM doesn't respond after a 
suspend/resume in case
it wasn't loaded before that. With this change/check, suspends work fine 
in this scenario
for me as well. Applied to:

github.com/srajiv/tpm.git next-tpm-fixes

Thanks for the fix Stefan.
Rajiv