Re: [PATCH] [RFC] tpm_tis: tpm_tcg_flush() after iowrite*()s

2017-08-14 Thread Haris Okanovic
On 08/08/2017 04:58 PM, Jarkko Sakkinen wrote: On Mon, Aug 07, 2017 at 09:59:35AM -0500, Julia Cartwright wrote: On Fri, Aug 04, 2017 at 04:56:51PM -0500, Haris Okanovic wrote: I have a latency issue using a SPI-based TPM chip with tpm_tis driver from non-rt usermode application, which induce

Re: [PATCH] [RFC] tpm_tis: tpm_tcg_flush() after iowrite*()s

2017-08-14 Thread Haris Okanovic
On 08/07/2017 09:59 AM, Julia Cartwright wrote: On Fri, Aug 04, 2017 at 04:56:51PM -0500, Haris Okanovic wrote: I have a latency issue using a SPI-based TPM chip with tpm_tis driver from non-rt usermode application, which induces ~400 us latency spikes in cyclictest (Intel Atom E3940 system, P

Re: [PATCH] [RFC] tpm_tis: tpm_tcg_flush() after iowrite*()s

2017-08-08 Thread Jarkko Sakkinen
On Mon, Aug 07, 2017 at 09:59:35AM -0500, Julia Cartwright wrote: > On Fri, Aug 04, 2017 at 04:56:51PM -0500, Haris Okanovic wrote: > > I have a latency issue using a SPI-based TPM chip with tpm_tis driver > > from non-rt usermode application, which induces ~400 us latency spikes > > in cyclictest

Re: [PATCH] [RFC] tpm_tis: tpm_tcg_flush() after iowrite*()s

2017-08-07 Thread Julia Cartwright
On Fri, Aug 04, 2017 at 04:56:51PM -0500, Haris Okanovic wrote: > I have a latency issue using a SPI-based TPM chip with tpm_tis driver > from non-rt usermode application, which induces ~400 us latency spikes > in cyclictest (Intel Atom E3940 system, PREEMPT_RT_FULL kernel). > > The spikes are caus

[PATCH] [RFC] tpm_tis: tpm_tcg_flush() after iowrite*()s

2017-08-04 Thread Haris Okanovic
I have a latency issue using a SPI-based TPM chip with tpm_tis driver from non-rt usermode application, which induces ~400 us latency spikes in cyclictest (Intel Atom E3940 system, PREEMPT_RT_FULL kernel). The spikes are caused by a stalling ioread8() operation, following a sequence of 30+ iowrite