Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-15 Thread Jarkko Sakkinen
On Fri, Sep 15, 2017 at 05:59:21PM +0530, Nayna Jain wrote: > > > On 09/14/2017 04:40 AM, Jarkko Sakkinen wrote: > > On Wed, Sep 13, 2017 at 11:39:03AM -0700, Peter Huewe wrote: > > > > > > Am 12. September 2017 17:45:08 GMT-07:00 schrieb Jarkko Sakkinen > > >

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-15 Thread Jarkko Sakkinen
On Fri, Sep 15, 2017 at 05:59:21PM +0530, Nayna Jain wrote: > > > On 09/14/2017 04:40 AM, Jarkko Sakkinen wrote: > > On Wed, Sep 13, 2017 at 11:39:03AM -0700, Peter Huewe wrote: > > > > > > Am 12. September 2017 17:45:08 GMT-07:00 schrieb Jarkko Sakkinen > > > : > > > > On Wed, Sep 06, 2017 at

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-15 Thread Nayna Jain
On 09/14/2017 04:40 AM, Jarkko Sakkinen wrote: On Wed, Sep 13, 2017 at 11:39:03AM -0700, Peter Huewe wrote: Am 12. September 2017 17:45:08 GMT-07:00 schrieb Jarkko Sakkinen : On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: The TPM burstcount

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-15 Thread Nayna Jain
On 09/14/2017 04:40 AM, Jarkko Sakkinen wrote: On Wed, Sep 13, 2017 at 11:39:03AM -0700, Peter Huewe wrote: Am 12. September 2017 17:45:08 GMT-07:00 schrieb Jarkko Sakkinen : On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: The TPM burstcount status indicates the number of

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-13 Thread Jarkko Sakkinen
On Wed, Sep 13, 2017 at 11:39:03AM -0700, Peter Huewe wrote: > > > Am 12. September 2017 17:45:08 GMT-07:00 schrieb Jarkko Sakkinen > : > >On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: > >> The TPM burstcount status indicates the number of bytes

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-13 Thread Jarkko Sakkinen
On Wed, Sep 13, 2017 at 11:39:03AM -0700, Peter Huewe wrote: > > > Am 12. September 2017 17:45:08 GMT-07:00 schrieb Jarkko Sakkinen > : > >On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: > >> The TPM burstcount status indicates the number of bytes that can > >> be sent to the TPM

Re: [tpmdd-devel] [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-13 Thread Peter Huewe
Am 13. September 2017 11:52:12 GMT-07:00 schrieb Ken Goldman : >On 9/6/2017 12:12 PM, Jason Gunthorpe wrote: >> >> The problem with this approach is that the TPM could totally block >> the CPU for very long periods of time. >> >> It seems very risky to enable.. >> >

Re: [tpmdd-devel] [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-13 Thread Peter Huewe
Am 13. September 2017 11:52:12 GMT-07:00 schrieb Ken Goldman : >On 9/6/2017 12:12 PM, Jason Gunthorpe wrote: >> >> The problem with this approach is that the TPM could totally block >> the CPU for very long periods of time. >> >> It seems very risky to enable.. >> > >How would you

Re: [tpmdd-devel] [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-13 Thread Ken Goldman
On 9/6/2017 12:12 PM, Jason Gunthorpe wrote: The problem with this approach is that the TPM could totally block the CPU for very long periods of time. It seems very risky to enable.. How would you characterize "very long"? The TPM vendors confirm that they empty the FIFO at internal speeds

Re: [tpmdd-devel] [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-13 Thread Ken Goldman
On 9/6/2017 12:12 PM, Jason Gunthorpe wrote: The problem with this approach is that the TPM could totally block the CPU for very long periods of time. It seems very risky to enable.. How would you characterize "very long"? The TPM vendors confirm that they empty the FIFO at internal speeds

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-13 Thread Peter Huewe
Am 12. September 2017 17:45:08 GMT-07:00 schrieb Jarkko Sakkinen : >On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: >> The TPM burstcount status indicates the number of bytes that can >> be sent to the TPM without causing bus wait states.

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-13 Thread Peter Huewe
Am 12. September 2017 17:45:08 GMT-07:00 schrieb Jarkko Sakkinen : >On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: >> The TPM burstcount status indicates the number of bytes that can >> be sent to the TPM without causing bus wait states. Effectively, >> it is the number of empty

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-12 Thread Jarkko Sakkinen
On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: > The TPM burstcount status indicates the number of bytes that can > be sent to the TPM without causing bus wait states. Effectively, > it is the number of empty bytes in the command FIFO. Further, > some TPMs have a static burstcount,

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-12 Thread Jarkko Sakkinen
On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: > The TPM burstcount status indicates the number of bytes that can > be sent to the TPM without causing bus wait states. Effectively, > it is the number of empty bytes in the command FIFO. Further, > some TPMs have a static burstcount,

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-06 Thread Jason Gunthorpe
On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index 4e303be83df6..3c59bb91e1ee 100644 > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -1465,6 +1465,14

Re: [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-06 Thread Jason Gunthorpe
On Wed, Sep 06, 2017 at 08:56:36AM -0400, Nayna Jain wrote: > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index 4e303be83df6..3c59bb91e1ee 100644 > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -1465,6 +1465,14

[PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-06 Thread Nayna Jain
The TPM burstcount status indicates the number of bytes that can be sent to the TPM without causing bus wait states. Effectively, it is the number of empty bytes in the command FIFO. Further, some TPMs have a static burstcount, when the value remains zero until the entire FIFO is empty. This

[PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance.

2017-09-06 Thread Nayna Jain
The TPM burstcount status indicates the number of bytes that can be sent to the TPM without causing bus wait states. Effectively, it is the number of empty bytes in the command FIFO. Further, some TPMs have a static burstcount, when the value remains zero until the entire FIFO is empty. This