Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On 8/14/2017 6:10 AM, Jarkko Sakkinen wrote: Nuvoton, ST Micro, and Infineon confirmed that the TPM empties a byte from the FIFO in under 1 usec. So, even with a static burst count, the entire FIFO would empty in under 10 usec. Does this break anything lets say in a decade time frame? If it

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Tue, 15 Aug 2017 18:02:57 -0400 Ken Goldman wrote: > On 8/13/2017 7:53 PM, msuchanek wrote: > > About 500 out of 700 mainboards sold today has a PS/2 port which is > > probably due to prevalence of legacy devices and usbhid limitations. > > > > Similarily many

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On 8/13/2017 7:53 PM, msuchanek wrote: About 500 out of 700 mainboards sold today has a PS/2 port which is probably due to prevalence of legacy devices and usbhid limitations. Similarily many boards have serial and parallel hardware ports. In all diagrams detailed enough to show these ports I

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Mon, Aug 14, 2017 at 08:03:05AM -0400, Mimi Zohar wrote: > On Mon, 2017-08-14 at 13:56 +0300, Jarkko Sakkinen wrote: > > > > > > I would like to see tpm_msleep() wrapper to replace current msleep() > > > > > usage across the subsystem before considering this. I.e. wrapper that > > > > >

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Mon, 2017-08-14 at 13:56 +0300, Jarkko Sakkinen wrote: > > > Since the main concern about this change is breaking old systems that > > > might potentially have other peripherals hanging off the LPC bus, can > > > we define a new Kconfig option, with the default as 'N'? > > > > > > Mimi > > >

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Mon, 2017-08-14 at 13:56 +0300, Jarkko Sakkinen wrote: > > > > I would like to see tpm_msleep() wrapper to replace current msleep() > > > > usage across the subsystem before considering this. I.e. wrapper that > > > > internally uses usleep_range(). This way we can mechanically convert > > > >

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Mon, Aug 14, 2017 at 01:51:30PM +0300, Jarkko Sakkinen wrote: > On Fri, Aug 11, 2017 at 11:30:19AM -0400, Mimi Zohar wrote: > > On Fri, 2017-08-11 at 14:14 +0300, Jarkko Sakkinen wrote: > > > On Wed, Aug 09, 2017 at 11:00:36PM +0200, Peter Huewe wrote: > > > > Hi Ken, > > > > (again speaking

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

Hello, On Fri, 11 Aug 2017 17:32:12 -0400 Ken Goldman wrote: > On 8/9/2017 5:00 PM, Peter Huewe wrote: > > > > Since we are the linux kernel, we do have to care for legacy > > devices. And a system with LPC, PS2Mouse on SuperIO and a TPM are > > not that uncommon. > >

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On 8/9/2017 4:43 PM, Peter Huewe wrote: Yes that's bad, especially with current msleep(5) is actually msleep(20). However, please also keep in mind SPI tpms show a much higher burst count value, (255) our I2C TPM SLB9645 even shows something in the range of 1k. :) One of our platforms has a

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On 8/9/2017 5:00 PM, Peter Huewe wrote: Since we are the linux kernel, we do have to care for legacy devices. And a system with LPC, PS2Mouse on SuperIO and a TPM are not that uncommon. And heck, we even have support for 1.1b TPM devices Understood. However, remember that SuperIO is a

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Fri, 2017-08-11 at 14:14 +0300, Jarkko Sakkinen wrote: > On Wed, Aug 09, 2017 at 11:00:36PM +0200, Peter Huewe wrote: > > Hi Ken, > > (again speaking only on my behalf, not my employer) > > > > > Does anyone know of platforms where this occurs? > > > I suspect (but not sure) that the days of

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On 8/8/2017 3:11 PM, Jarkko Sakkinen wrote: On Mon, Aug 07, 2017 at 01:52:34PM +0200, Peter Huewe wrote: Imho: NACK from my side. After these viewpoints definitive NACK from my side too... I responded to the thread comments separately. However, assuming NACK is the final response, I have

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Mon, Aug 07, 2017 at 07:55:49PM +0530, Nayna wrote: > > > On 08/07/2017 05:22 PM, Peter Huewe wrote: > > > > > > Am 7. August 2017 13:46:32 MESZ schrieb Nayna Jain > > : > > > The TPM burstcount status indicates the number of bytes that can > > > be sent to the

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Mon, Aug 07, 2017 at 07:46:32AM -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: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On Mon, Aug 07, 2017 at 01:52:34PM +0200, Peter Huewe wrote: > > > Am 7. August 2017 13:46:32 MESZ schrieb 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

[tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

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

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

On 08/07/2017 05:22 PM, Peter Huewe wrote: Am 7. August 2017 13:46:32 MESZ schrieb 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

Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount

Am 7. August 2017 13:46:32 MESZ schrieb 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